Testing the significance of a multiple R value from a multiple regression

Question

I'm an AP Statistics student (high school senior) doing a final project investigating the correlation between an "overall score" and five different "subscores" (the overall score is NOT calculated from the subscores; rather, each score is given separately). I'm interested in doing some sort of inference (like a hypothesis test) to see if the multiple regression model that I got with my sample data is significant; i.e. I want to see if the model can provide statistically convincing evidence that the population multiple R value is not equal to 0.

Could someone help me by telling me (in detail) how I would go about doing this inference? I only have Excel and RStudio at disposal (although I have very very little coding knowledge—almost negligible). I have studied one-variable calculus and have a very basic understanding of multivariable calculus, but I have never taken calculus-based statistics.

I've attached the multiple regression printout that Excel gives me for my sample data, just as an example of what I have at hand. (I've masked all the data.) image of Excel printout