Sorry for being so novice and I am not sure if it is the right forum to ask this question.
I usually shoot in digital bit I am recently got interested on 35mm film camera and planning to experiment with professional grade films.
I have used 35mm Film camera before (Pentax k1000) and used to shoot in consumer level films.

But being interested about pro-grade films I am completely novice about it.
So, my question is, is it possible to shoot in pro-grade films (like Fuji Velvia or Provia) using regular 35mm camera (Pentax K1000, Canon AE-1 or Nikon FM2)?
IS the working model is same as the consumer level roll films? I am hearing about slides and kind of confused, about the overall concept:

1. Does the pro -grade film have to be always slide films or is it possible to get as roll film just like consumer grade films?
2. what kind of films you suggest to use with regular 35mm camera? I am not professional, just a hobbyist but I like to achieve quality in work.

Please suggest and give your opinion.