I agree with the first reply. In-person jobs are a lot more easier to get when you’re a teenager + even if you suck at socializing/interviews, you gotta start somewhere ¯\_(ツ)_/¯ And while I’m not from the UK, my current job didn’t even really have me do a proper interview LMAO dunno if that’s good or not in regards to the business but as for me, it was very, very good. All they did was have me fill out an application form and asked me the basic stuff (ex: “when can you work?”). Then again, I originally volunteered at the place :p so my familiarity likely influenced the hiring process. Still, there’s definitely jobs that are always looking for new people, especially teens. They obviously wouldn’t expect you to be excellent at...well...anything, tbh. As long as you have basic human decency and can wear mostly clean clothes, you’ll likely get the job.
Though, I’ll suggest one remote job: commissions. Dunno if you’re an artistic/creative person but if you are, this is the number one path to take imo. You get a lot of control over what you make and when you make stuff, but obviously the catch is that it’s not a very reliable way to make money and/or obtain working experience. Still, it wouldn’t hurt to try it out if you wanted to! I don’t really have any tips for starting out since I’ve never actually done any commissions before haha but I’ve had artist friends use Discord for specific commission servers :0 If you have a decent following on a social media account, you could also just advertise your services on that as well