Yo quise viajar a Guatemala para las vacaciones, pero no pude.
Both quise and pude are conjugations in the preterite tense. The preterite tense is one of two simple past tenses. We use it to describe actions that took place or were completed at a certain point in the past. So this sentence translates into:
I wanted to travel to Guatemala for vacations, but I couldn't.
Both conjugations matches the first person singular.