Congratulations! The ETX-80 is a great, fun little scope. For lunar observing, I'd recommend the Orion V-Block. It does a great job of improving contrast and making subtle details pop out. I also purchased the 6.4mmEP...images are a bit dim, but it's a must when you just need a bit more magnification (and it's perfect for the Moon). I also purchased an Astrozap Baader solar filter...but there isn't much to observe on the Sun just now.

Those are the items I'd suggest right of the bat...other accessories will depend upon how and where you observe (LPR filter, camera adapters, etc.).
Craig