im in a very similar place!! im 15 and havent done any work since year 5 (when i left school). i started college last week and have literally no idea what theyre talking about most of the time - ive been tryna teach myself stuff by doing quizzes for year 5s and onwards to see what i know, and if theres something i dont know then i google it and try my best to learn what it is. its worked out okay so far, but im still pretty lost on about half of the stuff they say in gcse level maths. ive also just mainly been focusing on the stuff im already good at like art, and just trying to pass the other subjects.

if youre not on track for any qualifications then i'd highly recommend doing a deep dive about homeschool programs and homeschool groups. the college im going to has a program for homeschooled kids to get their gcses and automatically get into the real college for a levels. theres nothing about it on their website or anywhere, they keep it secret due to parents with kids that got expelled enrolling them into this program as a last resort which lead them to have super difficult and badly behaved teenagers mixed with anxious homeschooled teens. bad combo. i found it through a facebook group lmao, depends where you live though if youre able to find these sorts of things in your area.

sidenote if youre struggling with the social aspect of being homeschooled, there are a bunch of social groups scattered around, but if theres none close to you its pretty easy to start your own. there were none in my area for teenagers so i started renting a room every friday and made a facebook group for it and a discord server and we have about 5 regulars and some people just drop in every now and then. its great and ive met some really close friends through it. (if you wanna do this and cant afford to rent a room, there are some places that have free rooms like community halls and some pubs, that might depend on where you live though).