When you start a new hobby, don't spend a load of money, in case you decide later the sport is not for you. Probably the most popular PCP is the Air Arms S400, for good reason. Its simple, accurate, and consistent. The build quality isn't as good as a Steyr or Daystate, but its a fraction of the price. If your main interest is targets, the Classic has more shots, so a flatter power curve. The shorter carbine is often preferred by hunters. Don't forget a decent scope. A 3-12 X 44, such as the Hawke Varmint 2 is a good compromise to start with, you can use it for ratting, general hunting, HFT, and long range plinking, they are about £100.
The best idea is to visit, or join a club, and see what people use. Clubs often have an air bottle you can fill from, which brings the cost down a bit.
Gus
The ox is slow, but the earth is patient.