Was bedeutet "Kursfest"?
I saw the word in a dialog in my book it says: "Ich muss noch einkaufen. Morgen ist das Kursfest."

Question

Answer

It means the party (Fest) of the class/course (Kurs) he or she is in. So he/she needs to buy food etc. for the party his class is having. (That is assuming the text is about someone enrolled in some kind of class; it's hard to answer those questions without context).

Answer

In diesem Kontext:

Kurs = Klasse, Schule, Lehrgang, Unterricht
Fest = Party, Fete

Also sozusagen ein Schulfest, eine Klassenparty.