Good GMAT Prep Course for Someone who is not good at math

If I suggest you something, of course my answer would be biased
The best way to find out the quality of the course is by looking at the reviews. You can find reviews about various courses here:
https://gmatclub.com/reviews/

1. How long have you been studying? What material have you followed?
2. Have you taken any mock CATs? If yes, what are your scores?
3. When do you plan to take the GMAT.

You need to build the concepts/fundamentals before you jump in solving the problems. You can do so by choosing one of the following ways:

1. In person classes/private tutoring
2. Online classes
3. Self paced online preparatory course
4. Book heavy approach

Whatever you choose, make sure that you choose one. Because GMAT tests you on some concepts and fundamentals that you can learn from a course. Most of the prep companies including ours offer a free trial of the course. You can take the trial and see if the course suits you.

In addition to the preparatory material, buy the Official Guides too and the 4 official mock CATs. They should be an indispensable part of your preparation.

You need close to 3 months to prepare well for the GMAT.

1. Understand the concepts and fundamentals before jumping into problem solving
2. Solve full length CATs including AWA and IR. You can get two free GMAT Prep mock CATs and can purchase two more from mba.com
3. Make sure you solve the official questions from the Official Guide