I just finished year 11 and I'm hoping to get 10 A*'s-A's.
If you work really hard and put lots of effort in now, year 11 is going to be much easier.
There are going to be 6 gcse exams at most in year 10, but in year 11 there are going to be at least 12 so revise, revise and revise for the ones in year 10! Sometimes these make up 50% of the final grade for some subjects and you have a higher chance of getting a good grade as there are going to be less of them in year 10.
And for history, make sure you do well in the controlled assessment, it will really help in year 11 if you get a high grade in it!
The most important thing is to take year 10 seriously! Don't waste the year relaxing and taking it easy, it will really help if you work hard now!