Are my A level subjects are good?

Biology - Very respected, facilitating subject.
Government and Politics - Very respected, essay based, relevant to current affairs, interesting, etc.
History - Essay based, will certainly help you in the future when it comes to your university course. (Unless you a quant degree)
Sociology - Not respected much, but it could act as a subject which lowers your workload, and you could pick up a high grade quite 'easily'.

You'll be fine, whatever you choose to do at Uni, unless you want to do maths (you could still btw) your subjects will suit whatever you go on to do at uni!

ps, dont stress about the 'jump' from GCSEs to AS, you'll be fine as long as you work hard, especially with those excellent GCSEs. I did better at AS levels than GCSEs as i found it to be a lot less stressful as you do much less subjects and now have free periods which you can use to do extra work/do homework etc.

You've got a lot of humanities there, but as long as you keep the Biology to A2 (provided you still don't know what you want to do!) that shouldn't be a problem.
All of your A-levels are widely accepted subjects so you shouldn't have much of a problem with doors being closed to you on account of them, unless you're applying for a subjects that requires specific A-levels. I did a similar combination to you, except I did English Lit instead of Sociology, and I had no problem getting into Archaeology with them (and Archaeology is another gateway subject - the CEO of Lloyds Bank has a degree in it!).

Apart from sociology they are all very good. But you only need 3 for an uni offer so don't worry about taking one "easier" subject