Hello even i am not a Berber, I was asking some friends Berbers one day when I was living with them here in Marrakesh; I have asked them the same question, my friend told me : no it could be hard to learn all "shalha" because they are many, it's better to concentrate in one of them, specially talking to someone, because Berbers is talking not only a language to learn. and he told me a way, every word i know in "shalha", i replace it in my spoken, and like that i do remember it well, and understand the logical of word using. So, I think it's good to look for a friend to teach you his or her accent in shalha, and as you are good in Moroccan, you'll be able to communicate with some of them who knows the Moroccan Arabic. Regards.

the largest community of Amazigh and the most active part in Amazigh i mean who works hard on their culture and language is Kabyle dialicts, so you can find alot of teachers and vidoes songs that would help you learn it easily and it's really useful as well

Well, I'm native speaker , for High Atlas and Middle Atlas dialect they are almost the same the difference in some words but we understand each other but the north dialect "Rife Tamazight " it's different than High Atlas and middle Atlas dialect if you want practice just let me and good luck :)