Welcome!
If you are not aware, there is a Model Engineering Club in Milton Keynes. The address, according to the Station Road Steam, website, is The Caldecotte Arms, Bletcham Way, Bletchley, MK7 8HP
Would be worth making contact. You would, under normal circumstances, get some useful face to face advice, and / or demonstration.
You can learn a lot from reading the many posts on here. There is a VAST range of expertise on here!
FWIW, before buying a lathe, think about what you want to make with it, and then buy something a little larger, ready for when your horizons and ambitions expand.
If thinking of buying secondhand, unless you are used to machine tools, take someone knowledgeable with you to check the machine. Buying a worn machine, possibly with essential parts missing can be costly and still leave you with an expensive door stop!
Before launching into making a model, make yourself familiar with the machine, and the tools for it. You will gain knowledge and confidence.
Howard