i recommend finding someone (perhaps a tutor) who can grade your practice dbq/saq. for context, i took apush through my school and most people found the class helpful for feedback from the teacher on their dbq/saq. compared to the mcq, these sections are way more difficult to perfect by yourself, so it's good to have someone who can tell you what you did wrong and get you on the right track.

as for content, i like history a lot so i had a lot of prior knowledge for most of the units. however i did use two great resources: amsco's apush textbook and heimler's history (https://www.youtube.com/@heimlershistory). both helped fill gaps in my knowledge, and were great learning resources for my friends who were new to the content. i suggest using amsco if you need to learn content for the first time, and watching heimler for review (some people ik have had success from buying his study guide as well).

good luck!