How much work experience is a good idea for medicine

I think that would be fine, the main aim of it is to make sure it is what you want to do. I did a total of 4 weeks last year (just applied for 2018 entry), and I did really enjoy it, but from my personal statement- I could have just done a few days (the length isn't important to write). So 'quality over quantity' but as long as you get a feel for it and have examples to talk about at interview etc, anything over a week would be good.
In regards to applying, maybe just apply to your local GP and hospital, as these should have systems in place so it shouldn't be too difficult to sort out. If it fails, try a different surgery/hospital etc.
Good luck! If you have any more questions, feel free to ask- I was in your place last year haha!

Ha thank you!! I'm actually just in year 11 but teachers want us to apply already so...
I'm not on the best terms with the teacher who decided who gets the two gp placements the school has found, so I'm looking for some myself.

I did a three day work experience at a pharmaceutical company about a month ago, and I was hoping to either do stuff with a gp or hospital this summer, however, It would be nice to do the other one next year, so I don't want to apply lots of places to avoid not getting anything and end up turning someone down. So how many places should I apply to at a time? Surely just one would be too slow, but I don't want to do to many?
Would apply to a few of the GPs near me at once and then if that doesn't work hospitals, and if it does I'll try hospitals next year?