There are lots of excellent English language schools in the UK. There are at least 20 in Brighton, a city on the south coast of England. It can cost you time and money to study English on an English language course for international learners. Therefore, you might ask the question “Is it possible to learn English without going to English lessons?”
Learn English naturally
Yes of course it is. No doubt thousands of people every year arrive in England with a very low English level and learn English “naturally”. They speak to English people, work with English people, and eventually, they master English. You could too.