My budget is 200-300, at a push 350. I would probably use it to cycle more than 5 miles 2 or 3 times a month.
I was talking about pavements, is there a problem with that? Excuse me if I'm being naive, I'm 17 so I've not got the best knowledge of road laws.
If I was to be doing any cycling at the weekends, it would be on country side roads that are riddled with potholes, in-case that affects my choice.
Very hard to recommend a bike for someone your age, because at your age you will more than likely want to change your mind as to what you want to use it for. I would say buy a Hard tail mountain bike, This will allow you to commute to your gym, it will also allow you to go out and play on the trails. Something I have found Teens like to do.
Once you have been cycling for a while you will soon find out if you want to go for a road bike or continue with a Mountain bike.. Visit your local Bike shops, and see what they have on offer and what they recommend. I would recommend you also buy a copy of Cycle craft
http://www.cyclecraft.co.uk and a copy of the highway code, This will allow you to be more aware of the recommended practise for cycling on the roads, As to riding on Pavement, it can get expensive if caught, also what a lot of cyclist do not realise is if the pavement is split by a white line in two sections one for pedestrians and one half for cycles, it is against the Law for a cyclist to cross over the white line into the Pedestrians section and in some towns they will issue a fixed penalty fine.