Which sentence is correct:

I wanted to tell you something before I head to town.
or
I wanted to tell you something before I headed to town.

I think it is the first one, but I'm not sure.

Both work, but the first one is better.

The second one. In the first sentence, the verb tenses do not agree (Past/future).

Thanks

There is no future tense in either sentence. As I wrote before, both are technically correct, but the first one is better. It reads more smoothly.

The correct sentence is: "I wanted to tell you something before I headed to town."

In this case, the verb "head" is used in the past tense, so the past tense form of the verb "head" should be used ("headed"). The second sentence follows the correct grammatical structure by using the past tense verb form "headed" after the conjunction "before."

To determine the correct sentence, you can look at the context and the verb tense agreement. Asking yourself questions like "When did the action happen?" and "Is it in the present or past tense?" can guide you in choosing the correct verb form.