PandaThief wrote...
Ok i started it but yea where are all the mushrooms?O.O
The mushrooms are in the dungeon areas (the things that regenerate your stamina/mana). You may have passed a few in dungeons that you already completed, so I reccomend looking there. If you can't find any in those, there are always a few (I would say at least 1 or 2) in the final dungeon area, so you can get some there as well.
All in all I think this quest possibly requires a bit of prior planning since you can take the mushrooms without realizing its a quest later; however, I was still able to complete it regardless of not knowing about it, so you will probably be OK.