I'm finding all the tenses really hard to get to grips with, have you got any advice?

Absolutely. Firstly, I'd recommend taking some A4 sheets of paper and some coloured pencils. Take the present tense first and write out the -er, -ir and -re common endings, each on one page. Stick these around your bedroom! Next, do the same with the future tense, the imperfect tense and the past tense (le passe compose) and again, stick them somewhere clearly. Try and say them out loud regularly, even singing them if that doesn't sound too silly - this works for me, but it's not for everyone! Practice really does make perfect and I'm sure you will soon get the hang of them. If you have any questions about the tenses please don't hesitate to drop me a message, no matter how small or silly it seems :)