Just got back into Community College math. I'm in MTE 2 now. Help where I can study

Nov 2016
I really struggle with math and wanted a leg up to pass MTE-2.

MTE-2 Operations with Positive Decimals and Percents

Is there a recommendation or site I should focus on to learn how to ace the upcoming class?

One of my friends explained it deals with MTE 1- Operations with Positive Fractions combined

Math academy seems good but where should I put all of my focus at?