Can I teach myself how to play the ocarina?

No musical instrument can be self-taught, self-taught will only bring a lot of problems.

The foundation of the electronic piano and the guqin is certainly an advantage, but for learning the ocarina it is only an advantage in musical understanding, and does not have a great influence on the technique of learning the ocarina itself.

If you have a foundation in wind music it is relatively easy to learn, if there is no foundation at all it is difficult to blow the sound without understanding the breath.

It is recommended to go to a good teacher to learn properly. If you just want to play also go to find people who will teach you the basics of the method.