Don't be disheartened. Gmat test certain concepts in Verbal which we rarely use in daily spoken or written language. Go with your instinct. Would suggest you to go through First full Manhatten books and Concepts which you should know will be tested from
OG, Do basic practice math from this forum 500 level and after 15-20 days touch 600 level.
You should study concept first and then apply on problems, don't rush to problems, If you are good at math, It will take you 15-20 days to absorb all concepts and verbal will take a bit more time, Download resources from this forum like Math books, GMATCLUB grammar book, It will help you in getting to know Fine details you should look at questions.
Follow bunuel for math, for Verbal you can follow generis, Manhattenprep instructor,
Egmat and many more.
If you think to take some course first do study what course has to offer, Don't blindly go for reviews, as everybody has its own need. I am studying on all free resources available. Gmatclub has ocean of free resources. Use it.
Practice, Practice and maintain
error log where you are doing wrong.
Practice 2 RC questions daily after your study gets over, Powerscore CR bible is useful if you are getting problem in CR, If you don't have time to read book, many have made notes of that. Download and read. But this should be done if you already have pretty good hand on CR and have practiced at least 100 ques already. Otherwise you can read book to understand concept.
Always go from 500 -600 -700, If you think you directly want to solve 700 ques and see your caliber, you will be demotivated.
Best of Luck Studying. Just remember, GMAT don;t test your knowledge, It test your skills to solve and come out with solution as quickly as possible it ques are embedded with Tricks
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1 Kudos If i was least helpful to you.