How to write a (legal) contract for an API service

My startup is getting customers for our new API service -- we are using rapidapi, and it has the option to embed a Docusign contract. We would like to have a simple contract that puts into writing the simple agreement, but none of us are lawyers. How do we write such a contract? Are there samples online? Is it a good idea to have the contract? Any suggestions and best practices is appreciated! Thank you!