Reading/writing score

I got a 660 on R/W on my last test and wanna get to a 690 for a 1300 overall. (I suck at math, that 610 is the best I’m gonna get 💔). Just wondering if anybody has any resources for grammar specifically like tests or videos, cause I feel like I can get a 690 or higher by just getting better at that. Thanks!! Also any tips overall for that section would also be helpful.