Picture a little dark and distant to be sure, but looks like a ficus and probably ficus benjamina. Relatively forgiving. Tolerates wide range of light, soils and watering practices.

What direction does your window face? It would benefit from a few hours of direct sun, and if not supplemental light will help it stay compact vs leggy. When watering, water in three rounds 5 minutes apart to the point that it is running freely from the drainage hole each time(this ensures you leave no dry spots in the root ball). Then don't water again until the soil gets fairly dry(the pot will be considerably lighter when you pick it up). Always the first hurdle in bonsai, and perhaps the only absolute rule, is "keep it alive", so while you are getting good at that you can study up on modern soils that are better for your plant and help it grow faster.

You will find a lot on all of this at bonsai4me and kaizenbonsai on your side of the pond, and a good site originating here is bonsaihunk. Finally and most importantly, you must invite my wife and I to come see your lovely Wales :-]

Seriously though I hope you enjoy your bonsai experience. You can spend a lifetime of learning and still not know it all, so be patient.

ez