I was in the same boat as you a while back; I'm also a Warlock (Level 29 now). The first thing I did was focus on getting my Vanguard Level to at least 3; you get a free gift from Ikora everytime you level up your Vanguard from that point onwards. You should be able to hit Level 27 without applying any Ascendent Shards to your armor. Next, form a FireTeam to tackle the Weekly NightFall, Heroic & Heroic Strike for Legendary items - Ascendent Materials, Armor, Weapons, Motes Of Light and Strange Coins; completing Weekly NightFall gives you 20% boost on anything! Then, keep an eye out for Xur, Agent Of The Nine, who appears from Friday morning to Sunday morning and check if there's an Exotic armor piece you can buy for 13 Strange Coins or an Exotic Weapon for 17-23 Strange Coins (depending on weapon). If you're feeling brave and lucky, you can spend 25 Motes Of Light for a Yellow Engram for the Cryptarch to decrypt! If you do all those things, you're ready to tackle on The Vault Of Glass Raid for raid gear/weapon drops. I hope this helps you out! :D