My mum won't let me get a science tutor and I'm really unconfident with this subject. I need help and I need advice on how I can improve my skills!
read through the textbook and compile a list of questions you don't understand. Then post on TSR, search google or ask your teacher. Also do loads of practice papers and learn required practicals and equations.
Have you enquired as to why (e.g too costly)? Tbh you don't really need a tutor, though you can get help to any of your questions online. There are MANY online tutorials aimed for those studying GCSE/A-level (for example Khan Academy, and other very popular educational channel).