There are tons of ways and you have to start without worrying how it would end. Also i am giving a very general answer since I do not know anything from your background.
Few things you can choose from:
1. Real Estate: Learn how accounting works for real estate and how you can buy properties without any cash. Learn how you can partner with someone for equity deals. Learn how comparable work and how big multifamily deals are funded. Learn about how whole sailing works. You can also do apartment referrals to start making some money.
2. Stock market: First figure out the scam and open a small account and learn how to trade stocks. Do not lose big. Start small and lose small. Understand the psychology of traders who are taking other side of the trade.
3. Get education in a high paying sector. Currently it is either in coding or in some kind of handyman job (plumber)...do a bootcamp to start earning income and start saving some money for real estate deals or stocks. Note there are coding bootcamps which do not charge any money and you pay them based on your future guaranteed salary.
Of course I have not listed 1000's of other was you can make money!
Best way for an 18-year-old to make money are as follows:
Get Paid to Search the Web and Play Games: Swagbucks has been around for ages and they'll pay you for doing things you're probably already doing every day. Swagbucks has already paid out over 300 million dollars to its users in the form of PayPal cash, gift cards, and other rewards options.
Start a YouTube Channel: There are a ton of teenage YouTubers making thousands of dollars per month from YouTube ad revenue.
Here are some more ideas of what you could sell: You could also post these things on places like eBay if you wanted to sell them online.
Tutor: If you excel at a certain skill, you can capitalize on it. If you really enjoy tutoring, once you get into college you can look into higher-paying online tutoring jobs.
Learn a Profitable Skill: Once you're pretty good at the skill of your choosing, you can start making money from it.
Walk Dogs: Dog walking is an excellent way to earn some extra cash and get exercise at the same time. Once you get some more experience, you could put up posters around your neighbourhood advertising your dog walking services.
Babysit: Babysitting is one of the most popular ways for teens to make money because it pays well and it's a pretty easy job. Those people can then give you a good testimonial and recommend you to other parents. These services make it a lot easier to find new parents to babysit for. Once you're ready to take things to the next level, check out this babysitting business kit. It includes everything you'd need to run and grow a babysitting business smoothly and successfully.
Get a part-time job: Getting a part-time job is guaranteed money once you get hired.
Wash Cars: You could offer full exterior and interior cleans and get a nice little business going. If things start rolling and you enjoy what you're doing, check out this car wash business kit for more resources and guidance.
Ask Your Parents for Odd Jobs: It was a terrifying experience but the money was worth it.
Make an Etsy Store: Etsy is an awesome online marketplace where people primarily sell homemade goods.
Start a Fiverr Account: If you've been online before, you've probably heard of Fiverr. Simply put, Fiverr is an online marketplace where you can buy and sell freelance services starting at $5. Fiverr is one of the best ways for teens to make money online because it's such a flexible platform.
Rent Out Your Stuff: This little business earned them about $9.50/week without much effort on their part. I'm not saying you have to do the exact same thing, but renting out things you already have can be a great way to make money.
Collect Bottles and Cans: Every year a bunch of my family members get together and have a family picnic. If you wanted to do this, you could do what I did and wait for big family gatherings, or you could go around to your neighbours and see if they have any extra bottles and cans you could take.
Help People with Technology: Some simple things to do would be installing new software, fixing small problems, helping set up a new computer/phone, etc. If you ever come across a problem you're not sure how to solve, Google is a big help.
Create and Sell Art: If you love to draw, paint, do graphic design, or some other form of art, you have a skill that can make you a lot of money.
Enter a Skill-Based Competition: Some competitions even happen online so you won't even have to leave the house. This obviously is not a consistent form of income, but it is a way that you could make a lot of money fast if you are good at your craft. Plenty of businesses and blogs need photos to go along with their online content.
Enter Sweepstakes: Some of these people have won hundreds of thousands of dollars in prizes. Twitch.tv is a place where people live stream themselves playing video games. As a streamer, you can earn money from ads, subscribers, donations, and more.
Wash Windows: Once you have the supplies, gather a friend or two that wants to make some money as well, and go out looking for businesses with dirty windows.
Run Errands: If you have your license you can make a good bit of money running other people’s errands.
Clean Houses: If you like messes and you're good at making things more clean and organized, you could do well cleaning other people’s houses.
Start a Blog: You can then make money by teaching people what you know. Some bloggers even make millions of dollars a year because there are so many good ways to monetize a blog. Also, since blogs exist on the internet, they can be making money 24/7, even while you're asleep.
Sell in Game Items: I recently saw the movie Ralph Breaks the Internet and in it, there's a character called JP Spamley who teaches Ralph how to make money playing video games. Also, this probably will not make you a ton of money. If you're already playing a game though and you're really good at it, you may be able to make some extra cash from it.
Get Scholarships: With a good strategy, you can rack up thousands of dollars of essentially free money.
Gather Golf Balls: You could also ask your parents to help you get set up selling them online . Since you're a teenager, there's a good chance that your primary mode of transportation is your legs.
Deliver for Door Dash: As a Door Dash delivery person, you can set your own work hours and earn extra cash for each delivery you make.
Get Perksy: It's definitely the most enjoyable money making app I've ever used.
Save Your Lunch Money: If your parents give you lunch money for school, skip lunch and pocket the money.
Host a Poker Night: If you're a good poker player and you don't feel bad taking your friends money, host a poker night at your house. I recommend practicing a bit before you get into a real game with money though.
Reinvest in Your Business: If you've started one of the side hustles above like reselling things at school or starting a blog, your business needs money to keep running.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath
Look for problems that you can solve. Look for things that you are passionate about and go for it. Take a career interest assessment and see what career clusters best fit your personality traits. Skies the limit but you must start somewhere. Best wishes.