I travel to Des Moines every July to celebrate my grandma's birthday.
Since the subject is I (a wonderful grandson or granddaughter if ever there was one) the correct verb is the plural form, travel.
Example 2
You play saxophone in the school's jazz band.
Here the subject is you, so the correct verb is the plural form, play.
Example 3
I live next to a power plant.
That can't be safe. But we can safely say that live is the correct verb form here because it's plural, and the pronounI agrees with the plural form of the verb.