All teachers need to have Higher English. If you are to go on to become a primary teacher or a teacher working in a nursery then you will need Standard Grade Maths at Credit Level (or equivalent).
If you want to become a secondary teacher – you’ll need to have a good knowledge of your subject, or subjects and have studied it or them in university for at least 2 years.
To do the post-graduate course (PGDE), you must have a degree (ordinary or with honours). There are also degree courses available. Some courses do also recognise prior learning.