Why don’t the cullens like the mga asong lobo at first?? ( and vice versa) I mean they have a treaty and they don’t kill humans so what is their problem?

The mga asong lobo don't like the Cullens because as werewolves/shapeshifters, they have an intrinsic animosity towards all vampires. They smell vampiric venom and instantly think "enemy". Even though the Cullens don't hunt humans, the mga asong lobo think of them sort of like a ticking time bomb. The mga asong lobo who don't like being mga asong lobo also blame the Cullens' presence for triggering their phasing and the negative effect that's had on their lives.

The Cullens mainly dislike the mga asong lobo because they're picking up on this animosity and reciprocating it. They also feel that the mga asong lobo smell weird - kind of like a wet dog smell - and they worry about mga asong lobo being a danger to Bella because of how they can't always control their phasing when they're new to being a werewolf.