If you revise effectively, then it is honestly a really easy A level. You got an A* at GCSE, do you obviously have a good basis in it.
If you listen in class, you should be able to understand the concepts easily, and with practice using past papers, it is very easy.
The questions are simpler, or at least on OCR, because it is just the question, they don't talk about random people doing implausible things, is just the question, and it's actually much easier to get higher marks than at GCSE.
If you work hard, it will be okay. If you have any questions, use the maths forums, the people on there are amazing!