Fighting games are great for this. Street Fighter 6 is great (and the biggest). But there are others (Tekken, Mortal Kombat, Guilty Gear, Super Smash Bros, loads more and more upcoming new ones). Fighting games have usually have local clubs/events where you can play casual matches. They’ll also do local tournaments, and there will be bigger regional and national competitions to find. But it’s a great starting experience to go to a local tournament and lose £5 entry fee by losing 2 back to back best of 3’s.