I'm doing edexcel triple science too (year 11). When I have a topic test for example B2 topic 3 and 4, I go to all the past papers available on the edexcel website and answer the questions that relate to those topics for practice. If you don't understand something then ask your teacher to explain it to you again, or ask other teachers if there are any. It helps, trust me. In my year 10 mock exams I did an exam on B1 C1 P1 B2 C2 P2 and got A*'s for all but B2 (missed an A* by a few marks)
Print out the specification for each whole topic i.e P1 because they literally tell you what you need to get an A* in the exams
Start revising now for the first whole topic you have done e.g B1 because you will not have time in the future (I'm revising C1 now, I've finished revising B1).
You don't need a tutor at all! Science is not very hard and btw maths in physics isn't too challenging as there is a formula sheet given (unless you are year 10 then you don't get one [not fair at all])