once you guys get level 20 u need light to level up and one of the easiest ways is to start out with the daily story, u will get a blue engram once a day, then once u are a lvl 22 ,do the weekly heroic, then do a bunch of vanguard tiger to get lots of blue engrams which can have legendary stuff. then u get lots of vanguard marks from that and vanguard reputation to buy armor and weapons.hope this helps ( its the strategy i used and got to lvl 28 with)