The best way to learn is to move straight over tabs and onto to score, while playing scales and arpeggios to learn the fingerings. This will give you access to a lot more music options! (There is a TON of sheet for Trombone and Clarinet!)
The next thing to recommend is learning to transpose keys. This isn't as hard or daunting as it sounds at first! You kinda just pretend your instrument is tuned differently, this widens your options a lot.
Then the final recommendation following this would be getting yourself a chromatic tuner. One of the most challenging parts of playing the Ocarina is playing it in tune!
Some people kind of don't care, and just are out there living their best lives squeaking for the joy of it, power to them: But if you ever want to play with other people you want to learn to discipline your breath pressure to control your tone/intune.