On my first character I couldn't defeat O&S because I was leveling all of the stats. So much for tip "don't use guides or you'll ruin your first play". No. You will ruin your first play if you don't use guides at all because game tells you absolutely nothing and you'll probably end up with character with bad stats that requires good player's skill to deal with bosses. And you will not have this skill since you are new player.

So next time I used armored pyro/sorc with chaos zweihander and strong magic/fire damage. Even if I still lacked skill O&S was much easier fight. Same goes to 4 Kings or DLC bosses. I was terrible at parying or rolling but since I was like heavy tank shooting lasers and fireballs I could beat every boss with tanking and high ranged damage. So if you are new player with no skill use guides to pick your build cause good build can help you if you lack skill.

Quick Guide to new players:
WARRIOR - great choice for any pure physical build (strength, dexterity or both)
KNIGHT - crappy choice, you will soon learn than mobility is much better than being slow snail-tank, don't pick it!
WANDERER - best class for battle mage path that combines sorceries and pyromancies with dexterity weapons
THIEF - for speedrunners and more experienced players who use mixed builds, don't pick it!
BANDIT - probably best class for pure physical builds especially strength based, if you like smash things with big weapons it's your choice
HUNTER - used only for pure dexterity builds, if you want to stick with daggers and bows you can pick this one
SORCERER - great only if you want focus purely on casting sorceries most of the time, for mixing sorceries with melee pick something other
PYROMANCER - most balanced starting class with lowest level, used to combine pyromancy with anything you want, one of the best starting classes due to versality
CLERIC - best class for any faith focused build that combine miracles with any form of melee fighting
DEPRIVED - allrounder for mixed builds for more experienced players who know the game, don't pick it!

Of course all of this are suggestions. No one stops you from starting as knight and then focusing on sorcery to spam blue lazers. It's Dark Souls you can do anything here and there are no limts. But by following above tips you will have easier and faster results since each stat increase costs more and more and by making wrong choices you will have to spent hours grinding souls just to level up.

my go to pick is always the deprived, you can get good equipment at the start of the game and the stats are good

For minmaxing purposes one thing to keep in mind is that resistance points do not come out of the base level budget, so no need to look at that stat even when picking a class.

Our self-awareness and existential dread are our warning from whatever divine power sees us here.

Consume a canned cake

If you’re new to the game and don’t know what to choose, I’d recommend actually the lowest level class, the Pyromancer. Pyromancers start with Fireball, and Pyromancy spells in general require no stat investment in Intelligence or Faith, just in upgrading the glove for more damage. They shine as a mix of magic and melee. If you decided magic is not for you, it’s easy to abandon it altogether, or just use one of the best utility spells for more damage: Power Within. The only downsides to a Pyromancer is that they start with relatively low Dexterity and Faith, but besides that they’re almost as well balanced as it gets for stats. After you kill the second major boss, her sister gives you one of the strongest Pyromancy spells for free for just joining her covenant.
If it turns out you like spells more than melee combat, Cleric and Sorcerer are more specialists in Faith and Intelligence respectively. If you don’t like magic at all, Bandits are the way to go. Regardless, the first playthrough with a Pyromancer will really help you realize your play style.

I wunted to not die in one hit

I just started and t have not found my class yet but i am still looking and i hope to find my class some day.

Never really got the hype behind thief, all the equipment you get from picking the class can be gotten within the first 5 areas of the game and you can get the master key for only 5000 after ringing both bells. DEX is really good at the start but single digit strength almost nullifies any benefit that gives. Odd mix of intelligence and faith allowing you to use the most basic of all magic types but only enough attunement for 1 spell slot. Quite a bit of the same could probably be said for pyromancer (my personal favorite) though, so maybe I'm missing the point entirely?