Is this sentence correct? How do I use this grammar rule?

Is 昨日八時半ごろに僕は友達の家にあい行っていました

Also, how do I say I was doing something and something

Like, I know how to say I was eating = 僕は食べています but how do I say I was eating AND drinking

Would it be 僕は食べていて、飲んでいました

Thank You