I gave my GMAT and got a score I’m kinda okay with but i feel like I can do better now that I know what the test is like… can I take it again even though I already passed?
Yeah you totally can!! Doesn’t matter if you “passed” (there’s no pass/fail anyway, just a score). Many students retake all the time if they think they can improve. You can take the GMAT Focus Edition up to 5 times in a year, and max 8 times total.
I gave it twice 
First time was decent but not enough for top b-schools. Retook after like 2 months prep n scored way higher. As long as you wait 16 days between attempts, you good.