A completed action is usually told in present perfect. In German, this tense asks for an auxiliary verb conjugated in present and the participle of the main verb that describes the action.
You will find below sentences in present tense and, next to each, the same sentence in present perfect with blank spaces to fill. The main verb is in infinitive and in parenthesis at the end.
The auxiliary verb will always be either sein or haben, depending on the main verb. And the participle will always be the same for each main verb. These are the two things being asked in this exercise. When you are done, click 'Check my answers' to see the answer key.