I'm always trying to learn from other people's mistakes or experiences. It's served me well over the years, saving me much heartache, healing, and money.
Whenever you're working on a professional level, and even sometimes when you aren't getting paid, it's smart to have a contract that stipulates the terms of the services you are providing. A contract not only helps protect you legally, but it can also help either party remember what was agreed on.
More than once, I've had someone claim that I agreed to something, but I wasn't 100% sure I had. I've since learned to get it in writing. I missed out on getting part of a startup company sold for millions of dollars in my younger years because I did not have it in writing.
In this video from Chris Hau, he explains how he almost got sued over working with three different companies and how you can avoid that situation. Chris explains that you should have a contract checklist.
Chris explains that you should know and understand what you sign and get a copy of it. That contract should specify the scope of work, compensation, ownership rights, insurance and liability, cancellation policy, and governing law. I can personally attest to the late payment details, as this has helped ensure that I've gotten paid promptly with some past projects.
ASMP and other solid Professional organizations publish a lot of information on this topic. Why not join the professional organizations that can help educate you early in your career?
The best thing I ever did was hire a lawyer who works in the creative field and have them write me a contract. Cost me $500, I made more than 20x that back on the kill fee in the third project i used it on (was hired to do a large number of videos and the project got killed after 2). It's also given me MUCH more leverage when working with clients. They'll typically send a vendor contract that puts all the responsibility on you, and they own everything. I send back my contract and say, yours was great but this is specific to the photo/video field and will protect us both better than a generic contract. 80% of the time they say "sounds good" and sign it, 20% of the time I have to manually drop sections of my contract into theirs and I still get much better protection. All that to say... find an entertainment/creative lawyer, have them do all your upfront contracts, be better protected.