I ate banana.
I played baseball.
I had played baseball before I eaten banana.

{Banana} is a singular countable noun. We should add an article {a} before it.
We need to use the past tense instead of the past participle in the clause after {before}.

I ate a banana.
I played baseball.
I had played baseball before I ate a banana.

I ate snack.
I drank milk.
I had eaten snack before I drunk milk.

I had eaten a few snacks before I drank milk.

I played video game.
I drank cola.
I had played video game before I drunk cola.

{Video game} needs to be in the plural {video games}.

I played video games.
I drank cola.
I had played video games before I drank cola.

I ate apple.
I drank soap.
I had eaten apple before I drank soup.

{Apple} is a singular countable noun. We should add an article {an} before it.

I ate an apple.
I drank soap.
I had eaten an apple before I drank soup.

I read comic
I played frisbee.
I had read comic before I played frisbee.

I read a comic
I played frisbee.
I had read a comic before I played frisbee.