So I am taking Calc AB Honors next year, and I want to prepare for it over the summer. I usually go to Khanacademy to learn about the upcoming topics but Khan does not have like a category for this course. He has just a bunch of videos on different mathematical topics that relate to Calculus.
I was wondering if someone who took Calculus AB in their High School could reccomend me some areas of topics that I should start reading/working on?
There are tons of books that outline the curriculum for calc AB
Find a list of the topics covered and then use khan academy, because they do have great calculus practice, just not categorized by AB and BC.
You definitely need to learn limits, derivatives and definitive integrals. You can start there 
I think the main categories are Differential Calculus and Integral Calculus.
You need to be able to make connections between calculus concepts given graphically, numerically, analytically, and even verbally.
Since you are taking AB, avoid the following because they are primarily BC topics:
-Parametric, polar, and vector functions (you should have a basic understanding of the first two)
-Integration by parts, improper integrals
-Euler’s Method
-SERIES
There are probably more things to watch out for, but this list was made by a quick google search.
l’Hôpital’s Rule is moving down to AB, so make sure you understand that.
A visit to College Board’s site will give you much more information, so good luck!