Moving country - how does income tax in the UK work?

Hi!

I'm going to be moving to the UK soon for work, and will be staying for a few years. I have been told I will be making about £45,000 a year, and will be working in Oxford. This after tax calculator says I will make a bit less than £3000 a month - is this liveable in Oxford? I will need a car as I will be moving around the country (network maintenance engineer managing multiple offices in mainly Oxford but London too). I am wondering if anyone has a better idea of living costs in the UK and knows if it's worth staying in Oxford or living just outside it.

Thanks in advance!