More practice resources for JavaScript?

I like how Treehouse has their Practice things for various concepts of JavaScript, and the recommendations at the end of certain sections in the Full Stack JavaScript pointing to some of those Practices, but I'm finding they are not enough for me at this point.

I am most of the way through the Asynchronous JavaScript section, going through Promises, and I find that I can understand the concepts for what they are up to this point, and have an OK grasp on what they do, but putting everything together has become quite overwhelming. I get lost in the syntax of everything, have trouble writing the code correctly, and want some more small practice challenges to work on.

I really like how Treehouse sets up the Practices with comments for what they want you to do for the Practice, giving you a clear goal on what to do/make.

Is anyone able to suggest some more resources that can help me practice JavaScript concepts similar to how Treehouse does them so I can get more confident in actually writing the code and putting everything together? I feel like moving forward with the Full Stack JavaScript track at this point will lead to me falling further and further behind in my understanding if I don't get a bunch of this stuff really cemented in first.