Below are a series of links that you can go to to practice reading Spanish and in order to do well at HL Spanish you need to read as much as possible.
Remember it’s as important if not more important to focus on vocabulary as opposed to grammar. Knowing the rules of grammar is only of a benefit to you if you have the vocabulary to apply them to.
As such when studying Spanish you should incorporate as much reading and listening as possible. Reading refreshes vocabulary already acquired as well as introducing you to new vocabulary. Also try to identify any grammar that you have studied, observe sentence structure and see how this translates to English. Doing so will help not only with Reading Comprehension but also with Written Expression. Some of these sites also have review exercises to test your understanding.
A possible form of written practice would be to rewrite in summary form each paragraph from an article you’ve just read. This is excellent practice for opinion piece writing.