When I type F5, my terminal writes "~" but nothing happens, what did I miss?

In case you weren't attempting to make a point through irony, GP appears to be using "F5" informally as shorthand for "instruct your IDE to attempt to build and run the code". Presumably, that kind of documentation wouldn't normally literally say "F5" there unless a specific IDE had already been prescribed. The point was simply that the user shouldn't be required to do anything manual to set up the code, when starting from scratch, except perhaps to authorize the automated setup procedure.