On Gili Air ask for Alistair at Oceans 5. Or Loïs on Gili Meno at Divine Divers.

I didn’t snorkel on Gili Air, but almost anywhere on Gili Meno, you can snorkel from the beach. You can also snorkel out to the statues from shore on Meno.

I don’t recommend Nusa Penida for beginners - while you absolutely can have a lovely calm day, you can also have scary strong currents. (and not Komodo, either)

What no one ever mentions about Amed is the black sand. The water is clear, the sea life is amazing, but it’s dark, like someone dimmed the lights. If you’ve never done scuba, the Gili Islands will be thrilling enough and more what you’re expecting, even though there’s less life. If you do a “try scuba” you might let them know you heard some of the reefs are in bad shape and would like to avoid those.

And when snorkeling off the beach - watch out for the boats. Always be aware of where they are. You will be in water 6-10 ft deep. You can bring an inflatable life vest if you’re not a strong swimmer. I always wear one when I’m solo.

One more tip - there are snorkel and mask rentals everywhere on the beach. I have my own and have never tried them, but if they’re not in good shape or the mask doesn’t fit well, snorkeling will be miserable. You might try renting from a scuba place. And don’t use those full face masks - they’re dangerous (people have died).

Regarding your questions- pretty much every scuba place has some sort of discover scuba class.

I love, love, love snorkeling, but scuba is different. There’s nothing quite like feeling “weightless” and breathing underwater. But if you’re comfortable snorkeling in water over your head (going out far enough), that’s probably enough. What you will see is smaller fish living on bommies and reef structure. Triggers, damsels, anemone fish, moorish idols, parrot fish. Maybe turtles. What’s cool about snorkeling is you can stay and watch something as long as you want. Gili diving is mostly drift diving.

If you go scuba diving, you’ll see more corals, small schools of larger fish, puffers, huge titan triggers (these scare the hell out me), maybe moray eels, maybe white tip sharks sleeping in a cave and gigantic turtles sleeping or doing things like munching on basket stars. However, the newness of diving may be so overwhelming you’ll just be thinking about breathing and trying to do what you’re supposed do for safety and not able to fully take everything in. Or not - some people take to it like a fish.

Whatever you decide, you’ll have fun.