My advice would be:
1. Study hard in all subjects since when it comes to doing your GCSE’s those grade are important for university.
2. Stay open minded, curious and find your passion
3. Do extra-curricular activities like join a club in your school/sports team or doing something at your local youth centre
4.Look out for opportunities to visit universities or attend career related things. Your school may organise this, if not why not ask someone. Organisations like Smallpeice trust (google them) offer loads of residential courses for school students. I did that when i was in year 10 too.
5. Speak to your career advisor in school.