You need to hit lvl 20. After that you have a few paths, you need to partake in vanguard, that has been suggested already, or you can partake in the crucible. It's not hard to get rep and marks, it's just a grind. Same deal as vanguard, you can get armor at rank 2 with the crucible dudes. They are the ones right by your class mentor you met at the beginning of the game. Your mentor also sells the vanguard armor. The two on the way in sell the crucible junk. Third option is join a faction. You do this by seeking them out and buying a class item from them,I.e. Titan mark/ guardian cloak etc. after that all you do gains your rep with that faction. You will need crucible marks to buy armor from them once you hit rank two. Two ways to get marks. You can grind it out in pvp, or you can farm materials and exchange them for marks from the crucible dudes. Then give them to your faction. Every rank passed rank 2 with crucible, vanguard, or faction, get you one of their specific weapons or armor. All legendary. You also want to spend some time on getting your crypt arch rank up. This means getting engrams and taking them in. Once you hit level 10 with the crypt arch, he will start turning your blue engrams into purple gear. The chance goes up, the higher you level him and every time you do level him up, he gives you free junk. Once you hit about level 27, hit me up and I'll run the raid with you. At least the vault of glass. Weekly strikes, night falls, and daily strikes are a must. Let me know if you need help. I'm on ps3 phil_me81