jinx_58 Hey! 4th year student here! The subject selection process at uni firstly depends on what University you attend. I would recommend taking a look at your course progression map if they provide one to understand your courses core units/electives/majors this will help you select what to do and when! If you are super stuck, reach out to the university, they often have a call centre or email inbox dedicated to subject inquiries!
As for subjects per 'Term' - the word 'term' is often used at school and your school year is broken up into 4 terms. At university, you complete semesters, where the year is broken up into 2 main blocks rather than 4! There are typically 12 weeks in a Semester (not including exams/mid-semester break ect...) then you get a huge break in between! Some students decide to do trimesters, which are a little different and consist of 3 blocks however if you are doing the typical progression of 2 semesters per year, and you are a full time student, you often complete 4 subjects (commonly referred to as 'units').
If you are working or just need a little extra time you can do less than this, this is called under-loading! However don't be fooled - you still have to complete the units you un-enrolled from, just later, which will mean your degree completion will take a little longer!
Hopefully that helps!
Sven