@futurebird For me, the easy bit was seeing what my own language looks like when transcribed to IPA. I mean, I know how to say stuff, and seeing how it's transcribed helped me connect what I say to the IPA transcription. This was the basics for me.
As to other languages and phonemes that don't exist in any of the languages I speak well enough... If I'm really interested, I find examples and listen the pronunciations by a native speaker and look at the transcription.