If you are finding it confusing as to which level of maths you should take a good starting point is to visit the web page Advice on Choosing First Year Maths Courses.
It is important to know what your program requires for 1st year mathematics. Check the Handbook for your Program Requirements.
These Frequently Asked Questions may also help you.
If you require help please contact the School of Maths and Statistics Student Services on Level 3 Red Centre East Room 3072.