Supernatural acts

I’m a 16 year old student from Northwood school and I have a few questions I am hoping you can help with.

I’ve recently just finished reading the Qur’an and found it both an enlightening and thought provoking experience. I’d be interested to further learn about Islam though, so if you have any suggestions on how I should go about that, it would be greatly appreciated.

While researching Islam, I came across an interesting school of Sufi, Tariqa Casnazaniyyah. The followers of this group seem to be able to perform truly remarkable things, such as inserting metal rods through their cheeks without feeling any pain, without bleeding, without infection or, most amazingly, without suffering long term damage (it heals within hours or even minutes.) What is the mainstream Islamic point of view on such religious supernatural acts? Are there any practitioners of this school of Sufi in KwaZulu Natal, or in South Africa at all?

It’d also be helpful to know where a non-Muslim could learn Arabic? Is the Mosque an option? I’m not sure when or if a non-Muslim is permitted to enter a Mosque. I never had the chance to go with my school as I am not an art student (they recently visited a Mosque, Temple and Cathedral for an art excursion.) What is the general protocol?