I suggest sending out wedding invitations 8-10 weeks ahead of your wedding date. Some couples like to go farther out, especially if you're having a destination wedding. You'll want your RSVP due date about 4-6 weeks ahead of your wedding date. That way you will still have time to do last minute tasks like organizing the seating chart and ordering items contingent on your guest count.

If the invitations are shipping directly to you (no assembly required on my end, most common)

Digital ~ 5 days to print and ~3 days to ship

Letterpress ~ 15 days to print and ~15 days to ship

Foil ~ 15 days to print and ~15 days to ship

If the invitations are shipping directly to me (assembly required on my end)

Digital ~ 5 days to print and ~3 days to ship to me + 7 days assembly time + ~5 days to ship to you

Letterpress ~ 15 days to print and ~15 days to ship + 7 days assembly time + ~5 days to ship to you

Foil ~ 15 days to print and ~15 days to ship + 7 days assembly time + ~5 days to ship to you