As you have already learnt. arimasu is the verb for " to exist, to
be" of people or animals. Now you are learning the other uses of "arimasu"
having different meanings.
1 to have, to own
kuruma ga arimasu. jitensha mo arimasu.
I have a car. I have a bycicle, too.
ima, jikan ga arimasu ka.
Do you have time now?
2 to take place, to happen.
kyoo kaigi ga arimasu.
I have a meeting today.
konban 7 ji kara paatii ga arimasu.
I have a party from 7:00 tonight.