You can get an example project from GitHub and learn to write the smart contract code on a test net. Google for example walkthroughs where people have blogged about their example and the steps. I think most of the L1 Blockchains (eg. eth, dot, ada, algo, sol) have some starter projects, or others have made frameworks that make it easier (eg. truffle suite)
This would be a fantastic start: <a href="https://ocw.mit.edu/courses/sloan-school-of-management/15-s12-blockchain-and-money-fall-2018/index.htm" rel="nofollow">https://ocw.mit.edu/courses/sloan-school-of-management/15-s1...</a>