Well assuming you are not going to kill yourself, move to Liverpool or both, you have to decide if you are going to stay in one place or explore the world.
If you explore the world, depending on how long you live, you will eventually start to run into problems with food unless you are good at hunting. Also when you are ill what could be an inconvenience could kill you.
If you stay in one place, largely, you can plan ahead.
So I would stay near where I am now unless I thought there was someone somewhere else.
I may spend a month or two drinking etc but once I had decided that I wanted to live I would start planning.
So you need food, water, shelter, entertainment and defence against wild animals (no people).
The food that is around will not last forever. Some canned food may be edible after 50 years but it depends on how it is stored. Canned food loses vitamins with time. Unattended buildings will get damp inside or animals will get in, something will blow and smash a window and get the cans wet, wild fire burns it down, flood etc. So after ten years you will start running into problems with quality and restrictions in type of food. If you stay in one place you can you can grow your own food. If you can get to farm animals before they die from lack of water or food you could release them so you could hunt them latter unless you want to become a farmer. I live on the coast so have eaten fish caught off the harbour, about 15minutes from my house. I am not into shell fish but if I wanted to I could collect them.
How much bottled water is there around? Many people do not use it and supermarkets only stock so much. How long will the bottles stay water tight? So you need to find somewhere close to a spring or well. Plus moving bottled water to wash in is hard work.
You need a place that is near supermarket, water, woods (for firewood), place to grow food and in my case the coast. The building you chose should have solar pv installed or be very close to one. The house should be in its own grounds but near other houses that are also separate. It would have to have fireplaces so you can burn timber and wood have to have a wood burning stove (since op says no vehicles they are a bit too big and dangerous to move on your own). You would strip the food etc out of the supermarket and store it in a number of the nearby houses. That way if something happens to one building or the supermarket everything is not lost.
Entertainment, well you can charge your laptop with your solar pv and play civ. And read books.
In the UK there are no dangerous wild animals but dogs would be a problem. So shoot and eat the dogs or just shoot them.
Since the op states that vehicles do not work it is just as well there are lots of nice yachts in the harbour. So once I have set up my base I would sail up and down the coast and across to France to see if I could run into anyone else but would not stay away for long.