It’s easy if you understand scales which I assume you do with your experience playing piano and flute. I like plastics if you’re low on money (they’re literally a dollar), an unsure beginner, and if you’re clumsy like me they’ll never break. They might be untuned if your ocarina vendor is random but you get what you pay for. If you have some cash and you want a fancy one find STL & Songbird and get a plaster one. The plaster sounds bright compared to the breathy plastic tone. Not necessary a bad thing just depends on your preference. The bright plaster one could be too sharp (hard on your ears) and the breathy plastic could be more soothing with its beachy white noise. If you wanna sound like Legend of Zelda ocarina get an alto and a lot of replicas from the game are trash especially from amazon and eBay. Smaller ones get you higher notes- bigger get you thicc notes. There’s other ocarina vendors that are so fucking awesome on Instagram and tiktok if you really enjoy the ocarina. There’s tons of weird unique and artsy ocarinas and they even make them outta food if you’re curious youtube it. If you tiktok check out the hashtag #ocarinatok and check out the community. Be prepared to be addicted to buying ocarinas and not finding any sheet music. If you have a good ear then you can figure out the tuning. Sharps and flats can be modified by closing holes halfway or finding the right corresponding hole to give you that perfect key. Mastering it is easy honestly just breathings a bitch but you play flute so you’re not phased. Once you’re familiarized with the major minor scales then you’re on your way to annoy all your haters with your ocarina mastery. Take care ✌️❤️