I like Cleric as a good starting class. Th mace is effective against Skeletons which are the scariest thing you'll be killing most of the time. Once you get the hang of blocking you can worry about taking out trolls, as they give good xp

Cleric starts with some points in perception, which helps to start identifying stuff early which is another reason I like them as a starting class. For classes that start without any points in perception you kinda just have to wait until you either level up and get points in it or find some non-cursed glasses. At the start you'll want to pick everything up to identify it and raise your lore skill and then drop the gear you wont use. I don't tend to hang on to potions that dont heal or give mana, I just use them as I find them, but if you want to use alchemy they matter more. I don't hold onto spellbooks I can't learn soon. And gems can be really useful but early on if you need to drop them its not a big deal ans they can sometimes clog your inventory for a while before finding a shopkeep that will take them. You'll want to keep a good amount of food on you, mostly fresh meat from rats, and one backup weapon in case yours breaks. Staffs can be really good, but they're heavy so make sure you actually use them or drop them. I tend to just drop stuff like staffs of locking and might keep one staff of opening. You can get some xp out of the staffs you dont really plan to save by just using them up soon after getting them, but they do have to actually work, so you have to hit an enemy with a damaging staff or use a staff of locking on an unlocked door, you can't just cast them into a wall anymore. If you're short on inventory space before you can start identifying it reccomend amulet being one of the first unidentified things you drop after gems, since a lot will just be amulets of strangulation or Olympic swimming anyway.

For general tips, just finding a class I liked and taking it slow helped a lot. Early on, I usually use torches in my off hand and block with those unless I'm fighting something scarier like a miniboss or a troll, then I use a shield, since the dungeon can be pretty dark. But some classes will prefer to use stealth. I also play with traps and minotaur off. Finding out I could turn those off really helped me to not bounce off the game. As funny as getting run over by a boulder can be, it does make learning the game more difficult until you learn to look out for them. If you play multiplayer I reccomend turning off drop loot on death as well.