So the game is quite janky and buggy for now but can still be fun once you get into it a bit. It is indeed quite grindy though. Fastest way to progress at start seems to be to spam fights against brown rats on the very first map in the fenced in area, mostly for the cat's fur which you need a lot of every 10 levels to level up further, and do the weekly quests which give enough XP to level straight to about level 30. After that next area for fast-ish farming is 1 zone right and 1 up (teleporter at top left of screen), enemies in the fenced in area as well there. Mage seems to be by far the easiest thanks to aoe and ranged attacks giving him initiative and more damage in every fight, while still being able to tank just fine once you get a few level ups. (To be fair though I haven't tried all the characters).
If you do get bored of pure grinding though the map is quite huge with a lot to explore and there are teleport keys that let you teleport anywhere, even the highest level areas without really taking risks (most enemies don't attack on their own but there are a few exeptions).
Most of the quest drops can be gotten from any enemy including those brown rats after you accept the quests, so you can just accept like 10 quests same time and then spam the fights.
When it comes to upgrading stats, you shouldn't try to min-max, mostly you either want to tailor them to the requirements to be able to equip the gear that you find or buy, or to the spells that you intend to learn which also have stat requirements.
The game can often get stuck on 99% or 100% loading when you first load your charcter, you might need to refresh once or twice to get it going.
Looking forward to playing some more once the major bugs get ironed out.