New on genshin impact, it's P2W or not

It isn't P2W. Even if you were to pay for primos and pull some 5 stars, it wouldn't really matter since there is no 'win' in the game.

Of course you'll do more damage with constellations that you pulled with money, but the game was designed so that it can be beaten with the characters given to us for free at the start of the game.

Another thing is artifact farming. Even if you pay to get more resin, the RNG will not give you any good artifacts just because you spent money.

TLDR: It's not P2W