First, the character is heavy as fuck, i choose the knight and i can barely move, the roll is a joke.
That's because you're wearing heavy armor. There are three kinds of rolls in this game: fast, medium and slow (commonly called 'fat rolls'). Which one you do depends on your equip load. 0 - 25% does a fast roll, 25 - 50% medium and >50% fat. There are further sub-categories (fast-fast, medium-fast and slow-fast, for example) but those are not to be worried about unless you're min-maxing.
Your knight is either medium rolling or fat rolling; I don't remember the weight of the starting equipment. Medium is actually still okay, but fat rolling isn't a viable method of defense. So that means you have to block all damage instead.
If you want to roll faster, just take off some armor. Since defense in this game revolves heavily around not getting hit in the first place, this shouldn't be an issue. I've seen people do naked runs just to get those fast rolls while wielding heavy weapons.
Im at the firelink shrine and i cant even beat two skeletons that are there close, dont know if its an area i should go right now since i almost do no damage but in anyway i suck at the combat.
Nobody does; those skeletons are a hint you're not supposed to go there until much later. I admit the game is very obtuse about it.
For the moment, go up and cross the bridge. This leads you to Undead Burg, the real first proper level of the game.
Cant even figure out how to use humanity or what kindle is.
Humanity is presented by the number in the top left corner, next to your health/stamina bar. There are two kinds: soft and hard humanity. Soft is when you're still undead (when you look like a zombie). This offer a passive bonus but otherwise don't serve much purpose. You can make this humanity 'hard' by going to a bonfire and reverse your hallowing, basically making you human again. The big draw is you can now summon other players (or NPCs at times). The catch is it also opens you up for invasions.
The other bonus of becoming human again is the ability to kindle bonfires. This can be done once in the beginning of the game and it basically improves bonfires so you get 10 estus flasks instead of 5. This only costs one humanity.
Do note the the Firelink Shrine is already kindled, so you don't need to do it there just yet!