Growing paw Paw's from seed

I found a paw paw tree last year and saved some seeds from the ripe fruit. I've kept them in the freezer since I know here in VA they would freeze over the winter. (First off, are they still viable? I collected them in fall of 2018.) Are there any rules for planting them or tips I should know? I figured it would be good to add the genetic variation from the seeds. Are there any reasons not to grow from seed? (Other than time to fruiting) I would appreciate any and all help, thank you!