As a developer who faced the same challenge before, I would say it is better to start with "what do you want to achieve?"

The word "Marketing" is like a non-techie saying, "I want to be a developer."

- Which type of development? Websites? Apps? Systems?

- Which programming language?

- Which cloud/no cloud to release?

If you want organic traffic, then focus on and learn SEO.

If you want to spend money, learn ads.

If you want to build a personal brand, learn social media (focus on one platform).

Pick a goal, find how you can achieve it, make a plan, and execute.