My father's evaluation of taste wa said that it's “not so good”,” and my mother's said it was, ”so so”.”

This is how we'd say or write it in the US.

People have very different tastes in ramen, so I don't think what people's evaluations are say is very reliable.

Your sentence is correct but this is more how'd we say it in the US.

My father's evaluation of taste said it was “not so good”, and my mother's said it was ”so so”.

To sound more natural here I'd use "say". Or "my father's opinion was..."

People have very different tastes in ramen, so I don't think people's evaluatopinions are very reliable.

"Evaluation" sounds very formal, so I've changed it to opinion here too.

I hope it's delicious.

I hope it is too! :)

My parents went to eat there a while ago.

"a while ago" feels strange here, since you already explained that the ramen shop opened a month ago.
"My parents went to eat there" or "My parents went to eat there shortly after it opened" feel more natural.

My father's evaluation of the taste was “not so good”, and my mother's was ”so so”.

People have very different tastes in ramen, so I don't think people'stheir evaluations are very reliable.

Already introduced the subject, so it's typically to refer back to them instead of repeating the noun