Where can I find a BRUH soundfont?

Do you mean "brush", as in drums? Most soundfonts probably have these sounds, but they are tricky to find - you need to switch to one of the brush drumsets, and grab the appropriate MIDI pitches used by that particular soundfont (unfortunately there is not as much standardization of this as for other sounds).

Best thing to do is to make one yourself. Download the sound effect as a .wav file and import it into Polyphone.