- cryptozpmbies Learn the basics, and it's interactive. Somewhat outdated but good place to start.
- etheruem developer All the fundamental knowledge about ethereum
- recommended dev setup
- best practices
- [https://ethernaut.openzeppelin.com/](security game)
- [https://capturetheether.com/](another security game)
or if you prefer proper courses
- Ethereum Blockchain Developer Bootcamp With Solidity (2021) My friend says this one is good
- Defi Dev Mastery I'm learning Flashloan course from this guy and it is okay, this one is more advance and focusing on building farms and DeFi related stuffs