I am from Hong Kong and my mother tongue is Cantonese. I didn’t learn mandarin in school but then I pick up mandarin by watching TV show, listening to mandarin music, speaking to locals etc. There are only 4 tones in mandarin, so it is very easy to remember.

Pick one sound e.g. ‘bo’ and pronounce the 4 tones of that sound, you will find that is not really hard to remember.

You seem to be very interested in Mandarin, I would recommend you self-learning by with this material Living Language Mandarin Chinese, Complete Edition: Beginner through advanced course, including 3 coursebooks, 9 audio CDs, Chinese character guide, and free online learning. It is better to learn alone first, before going for a teacher. Listen more, speak more, you will be fine.