Here are some links you may find useful:
PhET – The PhET website contains lots of physics simulations to test out. In addition there are biology, chemistry and even some geography too.
IOP – The Institute of Physics has lots of resources for students studying or looking to study physics. All Sixth Form Physicists should sign up to the 16-19 membership. It’s free and offers guidance on A Level and degree courses, careers advice and access to Physics World which older members have to pay for.
The Physics Olympiad is a challenging competition paper aimed at Upper Sixth pupils. There are several other competitions for AS and GCSE too. There are plenty of past papers and solutions online to give you a taste of what to expect.