When speaking about going to a place where goods are sold to the public, we typically use the article "the".

We say "go to the store" (not "go to store").

I need to go to the store again.

I need to go to store again.

When speaking about going to a place where goods are sold to the public, we typically use the article "the".

Go to the store and pick up your order.

You can use the definite article "the" even if the specific store has not been previously identified.

Your sister and I are going to the store.

She went to the store and bought some milk.

But you can use the indefinite article "a" to talk about "going to the store" in a general sense:

You can't even go to a store and feel safe.

Articles and names of common places