Answer: These are the right answers:
1. salimos
2. llegamos
3. tomamos
4. empecé
5. buscó
6. encontré
7. mostró
8. compró
Explanation: Just to elaborate a little on the answer, it can also be added that in this exercise they are asking you to use the so-called "pretérito perfecto simple," which is employed in Spanish in order to refer to actions that took place or were completed in the past. The speaker is describing a series of actions that she and her mom did in the past (left the house, arrived at the mall, and so on). Please make sure that you spell the conjugation of the first person singular of "empezar" (to start) correctly—it is "empecé," with a "c."