Nowadays universities and colleges welcome people from a variety of backgrounds and there are a number of different routes you can take including academic and vocational qualifications.
The exact qualifications and grades you will need for different courses vary widely. You can find out about different entry requirements by looking in university and college prospectuses. Most of these are now available on-line.
Or by searching information on the Universities and Colleges Admissions Service (UCAS) website
You can find out more about vocational routes into higher education on the Aimhigher website. This also has links to information for mature (over 21 years old) students or if you are returning to learn after a break from education.