Don't worry about perks just yet. It is better to get your light level up first so you'll get better gear. Use gear and weapons with the highest light level and equip better ones as you find them. When decoding engrams, equip the gear that gives you your max LL and decode engrams one at a time. Once you decode and engram, check the LL stat, if it's better, equip it and decode the next one. When you get to the point where you can do the Vanguard strike playlist, run 5 -10 in a row. The longer you stay in the same lobby, the higher the chance for better rewards. Once you get to 260 -280 LL, start running Vanguard heroic strikes and do the same thing. You will start to get more legendary drops and that's the point where you can be selective about the perks. If you find a legendary that has the perks you like but it's LL is lower than what you have equipped, keep it and infuse it with other gear drops to boost it's LL to where you can wear it. This will put you in the upper 280- 290 LL range within a few days. Finally, if you have legendaries that you won't use, don't be afraid to dismantle them, you'll get 3 marks for un-upgraded and 5 for upgraded gear. It's a good way to stock pile marks for infusion or vendor gear.