epidemic

i have about 1.5k+ for a bike safety wise i would say 400ish

I am a 46 year old male going in for his CBT on Nov 9th I have never had a car or bike in my life. If at all possible what advice can this old man get, it will be for a 125cc geared bike for now till i get some experience. 1.what would be a good bike for a guy like me? 2.what type of PPE would you recommend? 3.should i start to revise for theory and so on now or wait a little ? Any advice welcome