Mdgardengurl, you collect seeds from the inside of the passion fruit once they're ripe. Do you know what types of passion vine you have? Many of the hybrids are fully or partly sterile and don't fruit easily, if at all. Most of the others need a non-clonal companion to cross-pollinate, although many different species can cross-pollinate and hybridize.

Once the fruit ripens, it will drop to the ground. You can open it and it'll be full of seed. THese can be planted immediately, although be warned that passis have a reputation of seeds that are slow to germinate.