I almost never use a bee brush although I have several of them. Lots of beginner beekeeping books, classes and videos will suggest including the bee brush in your list of beekeeping equipment.
I would suggest instead that you learn how to shake bees off of a frame. There are two good methods for doing this. The first is to grab the frame in the center at the top and bottom. The second is to grab the frame by its ears. Either way, give the frame a good quick shake. It might take two shakes at first, but soon enough, you’ll be able to shake all the honeybees off of your frame.
The problem I have with the bee brush is that it’s great at rolling and either angering or killing your bees. It also quickly picks up honey and wax, which impedes its brushing ability. A feather or a clump of long grass work about as well as a bee brush.