“Blockchain and money” course by Gary Gensler at MIT: https://ocw.mit.edu/courses/15-s12-blockchain-and-money-fall-2018/
“Decentralized Finance” course at UC Berkeley https://berkeley-defi.github.io/f21
“Decentralized Finance (DeFi): The Future of Finance” specialization offered by Duke University on Coursera https://www.coursera.org/specializations/decentralized-finance-duke
“Cryptozombies” an interactive Solidity programming language tutorial suitable for beginners. https://cryptozombies.io/