thanks for bringing up the topic again. I think it is a settings problem. I opend up the mixer thingy ( i dont remember the command, the one with the not so nice gui, and all the rulers where down. I dont really understand what all the rulers stand for, so I set them all to medim hight, but nothing changed.
@Guyverix i cannot play an mp3 or something. The “record and play” audio test doesnt help either. Honestly I feel a little overwhelmt (or felt, since its been a while) with the settings and the output, since I have really no idea what most of it means, so I would rather have the mic-problem working on my Debian system, which is maybe not the smoothest way but for my purposes and my motivation the best and most helpfull, I guess. If anyone has some input on that, I could focus on the sound problems with the ubuntu when I have some more time on my hands to get into the whole pulse-audio/alsa-mixer stuff 
thanks a lot, though!
and btw, @inallhissteps yes its the same VB all the time. there I just ajusted the volume with the volume bar in the GUI settings and it was done ^^