Lots of schools have sixth forms. You can stay at your current school or move to a new one. Sixth forms tend to be smaller, and offer more teaching structure and student support than colleges.
Colleges are often larger and more informal than sixth forms, and they offer a wider variety of courses (mostly technical), but they will expect you to be able to manage your own work and time effectively.
You need to find a school or college that offers the courses or subjects you are interested in studying, or the best route to the level of qualifications you want.
If you have special educational needs or other support needs, talk to your current school, they can help you make your choices.
If you have an Education Health Care plan (EHC plan) your school will help you with your plans or you could talk to the Local Authority about what do next.
Search and apply for courses through Kent Choices.