This is my ride: It's a 99 V plate Triumph Sprint ST 955i Triple, and I love it!
Only got back into biking over the summer, but rode smaller bikes from the age of 16 to about 21. Like Stranger says don't scrimp on the gear you buy, make sure you are well padded and protected, and like Stranger I have had a couple of off's too in my younger days
There are helmets and helmets, this website will help you with your choice on safety. https://sharp.direct.gov.uk/
You've only got 1 head, make sure it's protected!
As for which bike to go for well take your time and look around. Now is the time to buy because the traditional bike season has come to an end (april- sept usually) Don't be afraid to get an older bike, most bikers really look after their rides and there are some pristine models out there with low mileages for not too much dosh. Mine is an example of that
Happy hunting and safe riding