I believe the only "must have" will be a darning/fmq foot. Everything else is nice based on personal preference. I do not like gloves; I put KwikSort (bought at Staples) on my hands when I remember to use it. You can fmq with bare hands if your hands and arms are very strong. When I don't use KwikSort my forearms get tired and sore very fast.
Level quilting space around the needle area is most helpful. Even a small quilt gets heavy and the weight of the quilt will fight you and the needle if the quilt drags or catches on anything. There are a lot of imaginative ways to level your quilting space, and some are very cheap or free.
You didn't say what machine you have and that could make a difference for what you need. I've only fmq'd on Pfaff machines. My QE has a half way stop on the presser foot to keep the foot floating above the sandwich, with only minimal pressure when the needle goes down.
The ABSOLUTE must have is patience. You will not excell at fmq the first (few) times you try it, but it does get easier and better the more you try. After a fair amount of experience I found that I got cocky and thought I had it down. That's when I did the worst fmq I've ever done. The key is to start small and keep practicing.