No, this is not a requirement.
However, it would probably simplify things for you a bit. As much as you may despise legal jargon or the complexities of some contracts, often times its such details that save a business during a legal battle. I have no doubt that you could craft a contract yourself.
But, it takes more than just ability to do something to ensure that it covers all the necessary bases.
Your best option is to consult a contract attorney for help. It’s a small price to pay now for a bigger pay off in the future.
would be happy to put you in touch with a skilled contract attorney. They can help you craft a contract that includes all necessary information and is legally sound. Get in touch if you’d like to set up a consultation.