how to play this

----------------------0-0-0-0-0------
-------------------------------------
----------------------4-2-0-2-0------ what does this on a tab mean 1)pick just high e and g strings and miss out b?. 2)strum all three ? or 3) why are they lined up the same ,theres no hammer sign on tab, so do i pick the 4 -0 then 2-0 and so on please help us out

I understand you play with a pick right?
there are two possibilities here , first one is to pick the notes on the g string(yes a g-string) with your pick and the notes on the e-string with your ringfinger , second choice is to mute the b-string and strum the three strings with your pick, you just pick everything no hammer ons or pull offs , don't know where you get that

another thing you could do is change the tab
-------------------------------------
----------------------5-5-5-5-5------
----------------------4-2-0-2-0------

this way there's no string between it..

just see what works best for you and the song, gl