You use your forefinger (with middle finger on top of forefinger to add support) to press down on the three bass strings at the 4th fret, and strum once.
Then proceed to shift your fingers to the 5th fret in the same finger position and strum once again.
I do believe there's a sticky for tab-reading? Do a forum search yah? Happy learning!
Hybrid picking. Pick between your thumb and index as usual, that's for the bass note. The treble note, middle or ring finger will do. Or you might wanna try the classical guitar method, thumb on bass, index, middle or ring on the treble.