Have a chat with the admissions department for the paramedic science courses you are interested in. They will be able to confirm what you need. As you are 19, you will be a mature student by the time you get to the university stage, so it's likely you'll be eligible to apply with non-standard qualifications (something other than A-levels). For most, this is a specific Access course, done through a local college. It's a A-level equivalent for adult learners. You can do them online but I would recommend doing one face to face if you can.
The university will want you to have Maths and English GCSE at a 4 (C) grade (minimum). So evidence of a decent standard of literacy and numeracy is essential as will need these for completing, maintaining and interpreting important documents and doing things like drug calculations.
It's likely that the college you do the Access course with will also allow you to do the Maths and English GCSE (or adult learning equivalent like functional skills) alongside. That's something to be sure of because you will not be offered a place with an access course and no GCSE or GCSE maths and English equivalency. If they offer an equivalent, you need to check that it is accepted by the universities you want to apply to before you start the college course (otherwise you'll waste your time and be disappointed). They usually do accept GCSE equivalency from accredited schools but it is always best to check.
The admissions contacts are usually an email address included in the 'entry criteria' section of the course information on university websites.
Best of luck.