How to access a URL with JavaScript?

I'm new to javascript and am looking to make a chrome extension for my school that would pull specific professor results from rateMyProffesor.com.

My question is...how do I access a website with java-script, search the website for a professor, and then grab data about that professor and return it back to the extension. Hiding all of this from the user of course.

If this question is too broad I understand, if you can't help me please direct me towards the appropriate resources.