hey! guess what!
all of your contacts, downloaded apps, settings, and gmail are stored on the GMAIL ACCOUNT YOU SIGNED IN to your phone when you first got it.
you can actually throw this phone in the trash, get a COMPLETELY random android phone from another carrier, and if you were to just sign in with the same email you used for this phone. it would start syncing all your contacts and stuff from your old phone.
now you can rest assured that youll never have to worry about losing contacts from reseting the phone again.
I also highly reccomend you do not try Rooting your phone, sounds likely you could mess it up beyond repair and no best buy will help you then