24 in verbal is not that bad. But retaking in 30 days depends on your target score. You are already close to maximum in quant. Focus entirely on verbal and don't get over confident in quant. Try revising concepts math as well to increase by one or two points. For verbal it would be more helpful if you can post some more detailed information in what section, what topic you are weak in etc.
For CR: Use powerscore/MGMAT CR - both are good. If you getting way too confused with what is being asked and what you are supposed to do for CR questions then go for powerscore. If you are good at identifying the question types and scoring pretty decent enough then you can use MGMAT CR
Caution: Over usage of powerscore will be detrimental. Some say its excellent but this is my personal opinion.
For RC: One of the toughest section in GMAT and quite harder to improve upon unless you don't use the right strategy. The best solution is veritas RC or thursdays with Ron videos. You can find his links in this link
https://www.manhattangmat.com/thursdays-with-ron.cfm. Then its practice with right strategy to improve timing. With this you can improve RC. I shouldn't be suggesting this as i am too weak in RC but have seen considerable improvement with these.
P.S: All of Ron's videos will be very helpful and you can check those out if time permits.
For SC: MGMAT SC is the bible. Read it two or three times. Practice as much as possible. While practicing try to identify all the errors in each wrong answer choice. If you couldn't find one post it in the forum, discuss it. Most importantly actively involve in answering questions with explanations. That will definitely help you a lot.
As i said above 30 days is too short time for improving verbal. Depends entirely on your target score. If you aim for 700+ then it will take more than 30 days to improve verbal.
Hope this helps
