I aquired a Mossberg 12 GA. from my father that bought it for me out of the blue.

Well the barrel is a little bit rusty/ pitted on the outside and I was wondering what I can use remove the rust and the pitting?

I've seen that I could use a Blueing/ Rust removing kit, but I understand it could be tricky if you don't know what your doing.

It doesn't look like the barrel would be need to be resurfaced.
In and outside of the chamber is fine.