Can anyone explain how Bass Tabs work?
The four lines represent the four strings of your bass, and the numbers represent which fret you should be playing. G,D,A and E are the four strings in order, with G being the thin one closest to the floor and E bring the thick one closest to your face. So that tab you’ve given as an example is telling you to play the fourth fret of the A string (which is a C#) for one bar, then the fifth fret of the E string (which is an A), then the second fret of the E string (which is an F#). I strongly suggest a few lessons, if only to give you a grounding in basic music theory – you don’t need to know much to play rock and pop, but a good grasp of the fundamentals is very handy!