Is it better to have more gcses or a-levels when applying to uni? By the way I am at the gcse stage.
To apply for university you'll need UCAS points and/or particular grades in particular A levels (or equivalents). You can gain UCAS points from A levels (and other equivalent qualifications such as BTECs for example). You don't get UCAS points for your GCSEs (although you will need to achieve particular GCSEs to get into sixth form or college to study for your A levels). Most university courses also require you to have particular GCSE grades (usually in maths and English).
The more qualifications you achieve the more UCAS points you will amass. You might find this page about UCAS points useful. The higher your grades the more UCAS points you will achieve. You can calculate how many UCAS points you are expected to achieve here.
Many universities ask for a particular number of UCAS points to gain entry to their courses. Universities may also ask for specific grades from specific qualifications. When you feel ready to start your university research it'll be worth you checking whether the universities you're interested in ask for UCAS points and/or particular grades from particular qualifications for the course(s) you're interested in - you'll then have an idea of what you'll be aiming for. It'll also help guide your A level choices.
Hope this helps