OnePrep - Will it help me?

Hello,

I got a 1380 on my first diagnostic practice test 5 with an even split (I came in knowing NOTHING about how the SAT works and how to use Desmos). I'm taking the PSAT in about 20 days and I'm hoping to get 1450+ by then, and I plan on taking the November SAT and aim for 1500+.

In my situation, will focused OnePrep study help? Or should I focus more on khan-academy/other resources? For reading most of my mistakes were carelessness and misinterpreting, but for the math module 2 I didn't know half the material. I'm also a sophomore so I have a lot of time in case my current timeline doesn't work out.