Starting with oil colours

I’ve only used oil paints once in school and found them difficult. I’m used to acrylics, which are thicker, so I struggle to maintain oil paint consistency. So few doubts are in my mind : 1) How much turpentine should I actually use with oils? 2) Is it safe to paint with oils in a small room or studio?…considering the odour 3)Also, my palette and brushes are for acrylics. Should I keep using them or buy new ones for oils?? 4)And do I need to prime the canvas before starting?