Hi Haylee, welcome to the woods!
Are you using Flash? Flash's brush strokes are pretty unpredictable at the best of times, but it's partly about practising line control and partly about using tools to make your lines look better. For me in Flash, I draw with my brush smoothing on 20, which makes for a pretty knotty line, but then when the drawing is complete, I select the whole thing and optimise it (Ctrl Alt Shift C) on a low setting. I actually have this process bound to a shortcut key, so when I finish a drawing, I select it and hit my optimise shortcut a few times until it starts looking nice.
In ToonBoom, I find the brush strokes don't require quite as much maintenance, but I can still smooth the line with Alt Shift S. One or two passes of that is generally sufficient.
As for Photoshop, I have no idea how to smooth brush strokes after they're drawn, so uh.. I don't use Photoshop much
Hope this helps and good luck!