Thats a HUGE question!!!
I suggest you start with you're local fish shop, being from Liverpool there is bound to be a few good ones. Go in and ask them, the benefit is that they'll also be able to show you things at the same time, to give you the basics.
If you want your first tropical tank, i suggest you get a kit type tank, I've got two rena aquarama tanks that come with everything you need to start, all you add it water, gravel, plants and at the right time also fish

this takes the guess work out of things and at 60lt they are a manageable size but still with a decent water volume.
I see you've found the 'new to the hobby' forum, that's a good place to start, in particular the pinned threads, which are packed with info
Good luck, its a great hobby once you get into it

k:
Sam