Take the following & you should be fine ...
01 - CASH !!!
02 - DRIVING LICENCE (both parts &/OR PASSPORT for ID)
03 - PROOF OF WHERE YOU ARE STAYING - receipt of deposit
Now before you say I don't have a driving licence or passport then your last three bank statements for example. Just use your common sense & apply for a provisional as its a good proof of age. Also when you get to your accommodation ask them if they could provide something as proof of your staying there.
You can also now get these prepaid visa/mastercards as well which act the same as a credit card & I don't think there's a problem with being 17 to apply for one.
Hope that helps