brush tool not working

I have been watching the tutorial videos and though the videos do address the brush tool and how to adjust it, and although I am able to “adjust it” I am not seeing the affects of that adjustment. when I change the maximum it does work, but when I want a fine point therefore I change the minimum to the smallest percentage value I do not see ANY change what so ever. I have tried it on all the different brushes and no change. is there something wrong with my program? am I messing up? how do I get my brushes to obtain that fine point, especially when starting out?

Are you using a mouse or a tablet?

Pressure sensitivity does not work when using a mouse as there is no way to trigger the variable pressure.

If you are only using a mouse and you want a fine line use the maximum size adjuster and dial in a smaller size.