Hey,
Being in the Midlands means the sea is about 4 hours in every direction. For shore diving, Anglesey, Portland, St abbs are really good. Boat diving wemouth, plymouth, eyemouth. There are so many choices. My advice will be Join a diving club, it is the easiest way to build up experience. There are several good clubs around you which i can put you in touch with if you want. Or if you want to come have a chat in person im at Loughborough uni and the uni club meets every wednesday night. We can point you in the right direction.
I dived my first year in the uk in a wetsuit, it is manageable but can get pretty cold on the surface during winter. I still dive a wetsuit for shallow dives during the summer!