A great thing to do to prepare for this semester is to start getting familiar with the syntax of Javascript by practicing the creation of simple Javascript code. I recommend the Code Academy course as a good starting point.
First, sign up for an account on CodeAcademy.
Next, complete as many or all parts of the Javascript track on CodeAcademy.
The pace is a little slow at times, but just slog through it even if you have prior experience in Javascript. CodeAcademy estimates 10 hours for the whole course.
It’s a bit irritating that you have to upgrade to “Pro” to do some of the quizzes. You can do that if you want, but it’s optional as far as I’m concerned.
If you run across another interactive Javascript tutorial that you think is worthwhile, please post the link to the #pregame channel to let others know about it.