Yes, it's ungrammatical to say: Happiness awaits for you. The verb await is a transitive verb that is followed by a direct object; you don't use the preposition "for". So it's correct to say: Happiness awaits you. Instead of the await, you can use the intransitive verb wait, usually as (be) -ing form, followed by the preposition "for" as follows: Happainess waits for you/Hapiness is waiting for you.