I was wondering if you could drop some tips or topics that we should know. Especially for Maths 
As for tips, I can't say anything for maths except for memorise concepts and formulas, practice a lot, and don't stress. For topics, probably study these:
1. Financial Mathematics - compound interest, depreciation, interest,
2. Algebra - Factorising
3. Surds & Indices - Index laws, rationalising denominator, negative fractional powers
4. Simultaneous Equations - substitution, elimination & Inequations
5. Linear Relationships - gradient formula, distance,
6. Non-linear relationships - quadratics, graphing
7. Rates and Proportion - direct proportion, indirect proportion, conversion of percentage to ratio
8. Trigonometry - pythagoras, exact values
9. Geometry - angles of squares, shapes, parallel lines
10. Statistics - interquartile range, average, median, mean, mode
11. Probability - venn diagrams, conditional, tree diagrams
12. Polynomials - division of polynomials specifically
13. Functions
14. Circle Geometry - the formulas, graphing
15. Kinematics - time at which 2 objects meet.
(These are from Di.Dact from here:
https://atarnotes.com/forum/index.php?topic=183784.msg1101561#msg1101561)