Personally, my adventurer (who I need to get back to, thanks for reminding me) just kept asking for more and more quests, then picked all the ones that weren't monsters (i.e. bandits), wandered off there, quietly picked off supporters with ranged combat then if the main guy hasn't wandered off beyond my ability to find him (which happened at some sites, roll on the Tracking development item!) went in there and took him down. Do as many of these as practical (avoiding the big stuff that might be a problem, for now, and they're still on hold) and then wander back into the nearest town (or castle) to some manner of adulation (even if they hadn't been the ones asking me to kill these guys, they obviously would have if I'd enquired beforehand) and add to the possible quests.
As far as armour and supplies, I mostly looted from those I killed (having more often than not stayed travelling around the back end of nowhere, despite the proliferation of settlements, surviving on butchered wildlife, for which you need the sharpened stones (that are also fairly useful for throwing!)) because the shops I visit are often less than fully-stocked with anything I'm actually looking for.
I've survived a night-creature attack early on (was nearly next to a place of refuge) by somehow managing to dodge most hits, but a silly wandering local might have taken the brunt of the attacks and not one of my attempted strikes hit home, IIRC. From that encounter, I've decided to avoid the supernatural for the time-being. Who knows how lucky I've been in that regard, or if I've just been overcautious.
So, my advice about that monster would be to forget it, for now. Maybe I'm overcautious, but your approach seem to end up suicidal. I'm sure that if you ask a few more questions of the right people you can get a 'regular' enemy to stalk.
And as for stones... to paraphrase the MC at the Restaurant At The End Of The Universe: The secret is to bang those rocks together.