Beginner solution to basic quiz exercise, a la Gophercises
Two things I noticed:

    file, err := os.Open(path)
    correct, lines := 0, 0

    if err != nil {
        log.Fatal(err)
    }
    defer file.Close()



Handle errors immediately, don't do other things first:

file, err := os.Open(path)
if err != nil {
    log.Fatal(err)
}
defer file.Close()

correct, lines := 0, 0


Don't leave an opportunity to add more code later before the error handling by separating os.Open from if err != nil. Sooner or later you'll use file where it may be nil.
Creating a new scanner for each answer is slightly wasteful. Since you asked about potential tests, you can clearly test one or two question/answer cycles. To do that, you'll want to pass two io.Readers to quizLoop instead of a filename

func quizLoop(questions io.Reader, answers io.Reader, verbose bool)


You can pass the file and os.Stdin from main, and in tests you can pass bytes.Buffers, for instance, to supply test data.


I don't see an opportunity to leverage Go routines here. This program is inherently sequential. I'm sure you'll get an excercise for that later.