I'll chime in with the structured process I used. All of the following assumes you've been through fundamental lessons/the 7sage curriculum. If you haven't learned those basics yet, start there.
Then, begin with untimed drills. I did 10 LR question…
For drills, I do 1 passage at a time. Start completely untimed, giving yourself as long as you need to finish the passage and be fairly confident with most/all of your answers. After you can usually go -0 or -1 on the passage, start to introduce tim…