Apologies first English is not my first language.

I have a CS degree, and I've done a few ERC20 codes out of interest.

I also have BASIC knowledge of cryptocurrency.

I want to build platform like ethereum, or EOS (I know the latter hasn't made one yet).

Right now I have no real knolwedge (except for things you can find easily on google).

I really want to learn, but I don't know how.

I live in Korea and I can't seem to find a good course here. Could anyone recommend a course?

It can cost $$$. I found one on https://blockgeeks.com/pick-your-plan/ but don't know if it's worth the money.

I would really appreciate a reply. Thank you very much.