Long story short – after years of being a developer switched to managing our own product team and finally turned to marketing (and sales) almost full time. Since then, I've been teaching myself and dealing with pretty much every area of online marketing – from strategy to content to email to paid to social to search – with mixed results. However, I feel like I still lack the big picture, the underlying structure of it all – so even when I'm doing great in one particular area (say, SEO) I'm never sure I should be in this specific area right now at all, especially when good results in one area don't move the business needle at all. The lack of work experience as a marketer really doesn't help here. Can you teach all of this yourself being your own marketing team? Do you find a mentor or hire a marketing person and learn while working with them? Do you just take a break from your business and go work in marketing as an intern? There are tons of great guides on every marketing aspect, but what's the best way to get the big picture right? I imagine that's something a new CMO goes through when joining a new company.
To get the big picture right, pick up a good book on strategy. I highly recommend reading Good strategy bad strategy. It might not seem applicable to marketing directly but it will help you put together a strategic framework you can use to solve any problem and how to think strategically.
Once you have done that, put together all the high level questions you need to figure out in a doc: What problem are we solving? Who are we selling to? Are they looking for something like this or do we need to educate them about this product? What triggers/events lead them to look for something like this? Why are they buying from us? Where do they go when they are looking to buy something like this?
Once you have put these larger questions down, your day to day will help you figure these questions out and the more clarity you have on them, the more you will be able to focus on doing the right things instead of just doing a lot of things marketing blogs might ask you to do.