Restrict Multi-Site Customization

Hello, I’m trying to start a new website and have WordPress setup with multisite running successfully. This is the closest software I have found for what I want to do. I’ve used WordPress before, but never with multisite. Basically – what I want to do, is a user will sign up (eventually after a payment, but I can implement that later), and will get a webpage… lets say domain.com/mypage. That page will have a layout with pre-made areas, like “about me” and things of that nature. I want the user to ONLY be able to edit those fields… not create more pages, not add different things, just edit the given fields and save it. The top of the page will be universal across all websites, with a home button leading to domain.com, and a universal header image, etc. So basically, each site will only be one page with some minor field edits. Am I on the right track with multisite, or should I go with a different software? After lots of Googling, multisite was the best I stumpled upon. Thanks for the help!