Just get a soap like Stirling, Caties, Cold River, or Mystic Water and you can't go wrong. These are all lower cost - under $20 and work really well based on personal experience.

I don't use any pre-shave prep - just the soap.

As far as post shave I use different aftershave splashes like Fine, Pinaud, Captain's Choice, or Chiseled Face. There are others so find a scent that you like, again the ones I listed are under $18 so you don't need to spend a lot.

Stick to the basics at first and learn the technique first and later experiment with different soaps.