Hi everyone!

We are getting married in July and just sent our invites out. An older couple sent their RSVP and can attend our wedding. I got home today to find they had send a very nice gift from our registry. I'm assuming this is a wedding gift, right? I've just never heard of sending it early. Should I send a thank you note now, or wait until the wedding? If I do send one now, do I send another after the wedding thanking them for coming?
Sorry if these are silly questions, I just truly don't know!

Thanks for your help!