Guys I need some help in the craft and structure as well as the information and ideas sections of reading and writing. Any tips on how to improve???

I booked the March SAT and the June SAT as a backup. Now I need some tips from you guys to help me improve my English score from the 400s. From where should I start? As you guys remember, my parents do not want to spend a dollar on this prep, so I have to work harder, and hope that Khan Academy can help itself. If you guys have any free resources, pls provide them. It will be a great help. I want to know: in this community, am I the only one taking the March test, or are others taking it as well? Most of the seniors were seniors.

I think that both the rw modules werent too difficult? The reading passages were BRUTAL so were the tables. I saw everyone had like a question w tables so buckle up ig. Also the questions w the student notes were also harder than normal. The math part was okaaayy. Id say medium-hard.

Another SAT comes to the end -- how did you do? https://www.youtube.com/watch?v=L4HW33SgZlM&list=RDL4HW33SgZlM&start_radio=1

I am confused on how to get better at sat vocab as it is my main problem during the reading and writing portion of the test. (not in module 1, but in 2) And when I say I'm horrible at it... I mean it. Almost all my vocab problems that come up while doing a practice test I get wrong. I have tried to do practice problems of sat vocab questions in oneprep, but in the end, I got all the -hard- vocab questions wrong, with no signs of improvement. I've seen many youtube videos contradicting eachother on whether to study prefixes, and I am utterly lost on how to study the vocab portion for the test.