There are very good beginner video courses for learning Ethereum and Solidity.
https://www.udemy.com/topic/solidity/Write in more detail what you want to study?
Do you want to program smart contracts in the Ethereum ecosystem on solidity language?
Or do you want to understand how smart contracts work and be able to analyze information from them?
I hope you don't want to write an exploit that will hack the Ethereum DeFi ecosystem