Once upon a time, two SATs ago, I taught SAT prep for a national company. And the bad news is the reading section score is very stubborn. There are a few read the question first, underline as you go tips, but the only real way to move the needle on the score is to read (especially non-fiction) a lot and take the strongest English and reading based history/ science classes possible. If you take challenging classes and read regularly for a year, you can improve it. So that’s what you need to do, if you have time.
The good news is that the math and writing & language sections are preppable. So focus there. My kid was able to go from missing 9 on the language and writing test to missing 3 on the last practice and 2 the day of by focusing on that section and working a few problems everyday for a month and reading the official SAT guide on what they were testing.
Good luck!