Bad grades at the start of year 12 - how to avoid?

ok i know this sounds kinda dumb but everyone says that their grades drop significantly at the start of year 12, and i don’t want that to happen.
how can i avoid that from the start and get As and Bs?? Is it just inevitable or can you start off well?

No that's not dumb, I was worried about it too. It's definitely not impossible to get A's and B's right at the start, but the change between GCSE and A-level will take a bit to get used to. I'm not sure what subjects you're doing, but in chemistry and biology a big thing that I found impacted my grades particularly at the start of y12 was the language I had to use in questions, it's like stupidly specific and the questions tend to dance around what they actually want you to say. You've probably been told this before, but regardless of your subject really do make sure you're looking at markschemes so you know what points you have to hit. Also I made massive word documents covering the specifications at the end of each topic which was quite helpful, since everything I needed ended up in one place. Either way though, it's alright if you see a dip, it's a learning curve and what you're getting at the start doesn't really reflect what you'll get in the end. Good luck