Hi i just started playing yesterday, and i am already lvl 90.

I am gaining this amount of exp for killing a large rat, is that normal ?

How much exp was u gaining when u first started?

There is a global xp buff top right click the green hour glass and you can see the multiplier which is why it’s so much xp right now

zaalah made it quite easy to catch up to the topend, since you gain early like 45% vs top end gets 10% ... right now the community is funneling gold into global boost for combat, which has atm a 200x multiplier

"normally" its more like 5-10 instead of 200 ;P so you joined to a perfect time since you gain massiv xp right now

Thanks for clarifiying.

You want to join a corp asap. Any corp will do for now.
Check out a beginners guide and the wiki in game.
Good luck and have fun.