Start with mastering Bitcoin: https://github.com/bitcoinbook/bitcoinbook.

You can read more about all the bips here: https://bips.dev/

And chaincode has a Bitcoin seminar and a lightning seminar that is very helpful(you can do self paced as theres not an organized group starting soon). And they are starting a “start your career in Bitcoin FOSS” program next month. https://learning.chaincode.com/#FOSS