Gelcoat
You could be well ahead of the game if you take it to a good fiberglass repair guy. Gelcoat is very difficult to apply without the proper equipment. Gelcoat unlike regular paint, needs to cure from the inside out. So it needs a wax barrier to seal out the air so it can cure. You can apply it with a small rubber squeegee, and seal it with wax paper and tape or cellophane, but you would still have to match the color and sand it with super fine wet or dry sandpaper, and it still won't come out looking all that great. If you can find someone who is good at it, ask to see his work. There are a lot of hacks out there who claim to do good work. Then, on the other hand, there are guys who do excellent work. We have a guy who works at a boatyard up the river from our club, who does excellent work. If you had a hole in your hull, he could reconstruct the damaged area and match the gelcoat so that you would never know that it was damaged. Believe me, I've tried to do gelcoat and I'm no good at it. If it's just a small area, it is well worth it to have an experienced pro do it. DIY gelcoating isn't worth the aggravation without the equipment and know how. Been there, done that.
Joe