You don’t mail the tickets. They get them from you or family after they have arrived. You can mail the announcements now or even after the event has taken place. “Announcements” are actually for after the event, not before. But for your high school it doesn’t make any difference, really.

Go ahead and mail out the announcements. You or your mom needs to meet with the out of town family before the graduation starts and hand them their tickets. The point of mailing out announcements so they can send a gift and/or card to congratulate you. Not everyone is going to want to come, probably only your immediate fam is going to want to come. Oh and Congrats and the best of luck in the future!!