I purchased mine to do my own quilts, it’s a hobby for me. I’m not the type of person who would enjoy doing it for others, as that is far too much pressure to meet someone’s “expectations”; hats off to those that do!
There are several Facebook groups for longarm quilters and I think you’ll find that most are very very friendly and helpful.
If you really want to do it as a business, talk to others and be realistic with your expectations. There are those that take to longarming like a duck to water and are amazing at what they do, then there are the rest of us. It takes lots of time, patience and practice to become proficient with your machine. Good luck and keep us updated!