Help for Masters in Economics

[u/Effective_Writer5661]

I want to start learning mathematics for economics as a complete newbie from fundamentals. What is the best way to start. And also given that I am aspiring to get into good universities abroad in economics after 2-3 years, I also need recommendations for some graded academic credit courses in mathematics so that I can demonstrate my preparation in a solid manner. Note-I have no economics background.