When reading this chapter, please keep in mind:
Colloquial German loves the perfect tense (Perfekt).
German native speakers will always tend towards using the perfect when they tell you what happened yesterday at the office.

To use the German perfect yourself, please ...
... combine the present tense of the auxiliaries ‘sein’ (to be) or ‘werden’ (to become) with the past participle of the main verb of your sentence.

When do you use the auxiliary "to be" and "to have"?

For most verbs you need the auxiliary verb haben ("to have").
You use sein ("to be") especially for verbs that indicate location or a state.