One of the first things you should do when you arrive in the UK is sign-up with your local GP.
You need to be registered with a doctor before you can use their services. Some GPs may not be accepting new patients so you may need to call around to find a space. You should be able to find one nearby your home pretty easily though and it’s easy to change if you move.
Many of the cheap UK travel insurance plans require you to be registered with a GP before they will cover you (which many people probably don’t know unless they read the fine print).
TIP: One thing that you’ll find useful to know is that the postcodes in the UK are specific enough (down to certain houses on a particular street) so that you can use it to perform just about any search on most websites, instead of having the enter the whole address.