Quartz brief is helpful for readings with relation to current news. It gives short digestible information with sources should you wish to dive further
YouTube has many excellent short history videos. You’ l find some on almost any stage of American History. Beware of bias though.
The Princeton ap books have lots of good information. They make it super fun to read. It is pretty thick though, but you can start later in the book and skip the pre bce stuff. It’s pretty good. I think like $20 on Amazon.