Play either the C major scale or the C major pentatonic scale (which is just like the major scale but with fewer notes).

Have a few goes through then try (at your own speed) with the C major backing track - click on the track in the list and it will start to play (after one bar rest and a count-in).

UKULELE:  C major   G major   D major   F major   C blues   G blues   D blues   F blues

UBASS:  C major    G major    D major   F major   C blues   G blues   D blues   F blues