How should I best go about laying Vinyl Sheet flooring over an MDF Floor? Vinyl is not cushioned?

My husband and I are pretty new to the whole DIY and are not to sure how to go about this. I have read that if the vinyl is not cushioned you need to use adhesive. What am I looking for and what is it called? Also the MDF we want to lay on is our 'floor'. We have an 85+ year old house with some dodgy floors, all a bit slopey in the 70's addition of the house. As it is impossible to get willing tradies where we live we put joists on top of our wonky floorboards and installed a new floor of 15mm MDF. Please tell me we can put adhesive on this. All answers greatly appreciated as we are in the throes of it as I type.