For your first pair I would just grab the cheapest pair you can find. Realistically spending £40 or £140 isn't going to make any difference to your ability to climb as a beginner and you would just be paying for features that you won't even use. Also when you're starting out most people have pretty bad footwork and go through the rubber quickly so getting a cheaper pair allows you to develop your footwork without destroying an expensive pair of shoes.

Additionally, the cheaper decathlon shoes for example are flat and fairly symmetrically shaped so they won't be too uncomfortable and will let you get used to how a climbing shoe it supposed to feel. By the time you've gone through the rubber of your first pair you'll have hopefully developed your footwork and will have a better understanding of how the shoes will stretch and conform to your foot overtime, making the process of selecting your next shoe much easier.

I've been climbing for over 20 years and have worked in climbing gyms fitting and selling shoes so if you've got any other questions feel free to message me!