Im looking for a acrylic nail brush but they have numbers on don't no witch one i have to get?

The size (the numbers that ae listed on the brushes) depend entirely on what you are using them for. If you are just doing a set of acrylics on yourself try to find them in a beauty supply store and play with them a little to see what you think will get the best coverage on your nail beds. You might buy a couple of diferent sizes just in case. When I used to do my own I had one specific size that I liked and it worked very well. Hope this helps!