This is an excellent question, I assume you mean digital education platform. Of course the question of starting is very broad. Please feel free to reach out for me to help you conceptualize, start and implement your plan. I highly suggest that you figure out the following.
A) What is the product or what are the services you want to offer? what makes them unique or attractive to the clients? what is the value of these to the clients? how are they different from competing services
B) How will you market the product and close a sale with end customers? This really matters as many startups fail because they cannot sell or marketing is more expensive than the product price. I also suggest considering pre-sales and community engagement before launch
C) Operations- how will you create the material or source the educational material that will be presented? Where will you find talent to support you (consider freelancers eg from Fiverr or Upwark in the beginning?
D) How will you finance the creation? Can you bootstrap your business model to something simple and not cash intensive? Can you use crowdfunding?
E) What is your overall business and financial plan? Happy to help draft one
F) Implementation- how will you implement it all and make the final tweaks such as to branding and messaging?

Hello Otatade Okojie here a good place to start is by researching your candidate and looking for a gap in the market. As you are looking at ed tech, you want to create a platform where you can engage the audience and quickly capture the data quickly. Have a strong strategy for sourcing content and engaging your key target audience. What is the theme of the platform?
What are the topics? What areas of education are your niche audience focussed on ? Who is your demographic? What will they be learning on the platform, what will your platform be providing that they won't be getting anywhere else? Is it speed learning? Certificates? Access to work placements, apprenticeships, internships? What is your offering? What are the strengths of the platform? What is its unique selling point? Have you thought about the different processes. Have you planned it? From brand design, inclusion of logo, market strategy, engagement, content pitch,.promotional content and hooks that could encourage influencers and candidates to share promo messages.

I think most of the answers here over complicate STARTING.

If you're looking at building out an EdTech platform you want to THINK about what will make you different - content, structure, the delivery of the education etc.

BUT, you don't need to overcomplicate STARTING.

If your niche is in paediatrics / family health, that might be all the thinking / planning you need to do. I would start by delivering that content and getting feedback.

If you're creating the content, create it.

If someone else is teaching out, reach out to experts and see who would get involved and what incentive they would be looking for (paid, free for publicity, advisory equity etc.)

Then create the content and put in on YouTube, or create a Udemy Course. Alternatively, hide the content and then sell the "Program" on GumRoad - when people pay for it, send them a PDF with links to the content.

Ideally, you want to get started quickly, get content up there, see how hard it is to get distribution (marketing it), start building your brand, and getting feedback - give away some programs for free to get reviews. Use the feedback to determine what your EdTech platform will look like.

All the best.