If you are writing lots of small programs for a C programming course, you are better off using a text editor like VSCode, Sublime Text, BBEdit, or TextMate to write your code instead of Xcode. Xcode requires a project to create an executable file. You can't just create a C file in Xcode and run it.
I know TextMate has a C bundle that lets you run your programs from inside TextMate by choosing Bundle > C > Run. I'm sure the other text editors I mentioned have ways to run your programs from the editor.
Topic:
Developer Tools & Services
SubTopic:
Xcode
Tags: