hi i'm in yr 11 n just finishing my coursework for textiles, if you have a passion for textiles i def recommend, esp in yr 10 before the coursework questions are released you will either be doing theory in your classes or just practice work for your coursework which isn't v hard and can be quite fun. my advice would be to make sure you're always on top of the coursework as soon as you start, when your teacher sets internal deadlines even if they seen really early they're there for a reason. the coursework is quite hard work, make sure you're not just doing the work in class but outside of it as well. even though it can be quite tough its like that for p much every gcse. i wouldn't recommend taking dt if ur already taking another coursework subject, i'm taking art too and i've fallen behind in both bcs of how much work there is, so don't put urself through that if u don't have to. for skills, you should know how to do basic hand stitching, and maybe be able to use whatever machinery they have in ur schls dt department, like sewing machines, possibly laser cutters, etc. if u don't go and ask your teacher how easy it would be to learn in time to start your coursework. if your school has an embroidery machine i recommend asking your teacher to teach you how to use that for ur coursework instead of using machinery that timbers and systems students would be using, like laser cutters and 3d printers, bcs its much easier, and you won't be waiting in a queue to use it, depending on how many people are taking textiles in your year.
idk if that made much sense but yh hope that was helpful xx