In general a 350 score is at the lower end of the scale (the scoring scale is 200 to 800), so you would be focusing on easier-level problems.
Have you tried taking a practice test to see what your starting scoring level is? If not, I would first learn the basics of each question type on the Q and V sections—just the very basics, enough to understand what to do for each type!—and then take a practice test to see where you are.
For instance, this article covers the basics for Data Sufficiency (DS), one of the two quant question types:
blog/2013/01/24/how-data-sufficiency-works/And this one talks about Sentence Correction (SC), one of the three verbal question types:
https://www.manhattanprep.com/gmat/blog ... em-part-1/If you sign up for a free account on our website, you'll get one free practice test.
You can then use the data from that practice test to figure out a study plan. You'll be able to see what your strengths and weaknesses are across the different question types and content areas—for example, maybe your algebra will be okay but you'll struggle with story problems that test fractions and percents. So then you'll know to study those kinds of problems.
Read this first:
https://www.manhattanprep.com/gmat/blog ... lly-tests/Then go and look at the articles I linked above for SC and DS. You might also want to browse our blog for other articles on the other main verbal question types (Reading Comprehension and Critical Reasoning). The other quant question type, Problem Solving, is just a standard multiple-choice math type. I wouldn't spend more than a week learning about the question types—maybe even just a few days.
Then take a practice test and use this to analyze the data:
https://www.manhattanprep.com/gmat/blog ... ts-part-1/And then decide what you need to study to get better! If you'd like to check your study plan with us, please feel free to come back and tell us what you think you need to do. We'll let you know where we agree and disagree.
Good luck on your practice test!