The main thing is to get to vanguard level 2 so you can start buying armor. Then you need to grind ROC strikes and get enough marks to buy all legendary gear. Once you hit 30 you can run Crota on normal and get light level 36 gear. It's just a big grind, stay strong guardian! Also don't bother leveling you're vanguard gear to level 31 since you will replace it with raid gear anyway.