If you're new to the Mixolydian mode, play through it slowly and listen out for the minor 7th G note. This is the only note that's different from the major scale. Playing the mode up and down the ...

you'll stick mostly with the G minor blues scale (G Bb C Db D F – G minor pentatonic with the addition of the b5). Finishing on G major's major 3rd, the B note provides insightful harmonic savvy.