Ive got a great video of my band playing, but since its not my recording, theres pretty ****ty audio. how can i clean it up well?
Try a noise gate and a low-pass filter to taste. Use a paragraphic eq to find the frequency with the most noise and hiss, then bring that down by a few dB. A multiband compressor can also help keep the frequency balance even if you know how to use it properly. There's only so much you can do, though.
^ What he said.