The title of this Website says it like it is! Got a few minutes to kill – just you, your uke and the Internet – then give Ukulele Beatles Fun! a try.
My suggestion is to ignore the fretboard and follow the chords and words at the top. In my opinion the fretboard uses some different versions of a few chords. Might be worth learning those, too, sometime.
The important thing is to crank up the speakers and just have fun!