descriptive statistics and analyses (group comparisons and/or association tests)
This line is key. It's not really R you're working through but the stats. I'd suggest those key terms above as a starting point for your search. It's also key to know what type of variables we're dealing with to help here.
I haven't given you a complete answer because that would violate our HW policy at talkstats. Our homework help policy can be found
here. We mainly just want to see what you have tried so far and that you have put some effort into the problem. When you've searched a bit and tried some things please share what you've learned and ask further questions.
PS when you say...
It is not completely clear to me which test I should run.
That's the art of statistics we all struggle through even seasoned veterans.
We have a great resource for helping to make these determinations (
LINK). In this thread (which is located in the FAQ forum of our website) you'll see links to various resources to help you make this decision.