Well... 3 blues at +21 and an exotic should get you to level 28. But really, if you can get to 27 you're into the Vault. Vault gear can get you to 30. Vanguard gear can get you to 31 with 2 pieces of +33 and an exotic... So long as you have a vault piece at +30. Going vanguard only will take forever. You only need Rank 2 to buy armor... But you need 2 commendations, one for a helmet, one for a chest - so now you're talking Rank 5 unless you're gifting them to yourself from another character. The items that need commendations cost 195 marks combined for just those 2 items. That's pretty much 2 weeks of max marks... Then you need 150 more for arms and legs... 2 more weeks. Just try to get to 27 and get into the Vault, save yourself heartache and waiting. You need 87 light to be 27. If you hover over the light number it should show the progress bar and number to the bars left.

Buy vanguard or faction armor. New monarchy gives some good stats but have a look around and aim for stuff that suits u.

Do bounties until you get to rank 3 vangard... then grind strikes to get currency to buy the armor...you should be able to get to 31 no problem.

You have to work on getting armor with higher [b]light[/b] rating. The more light a piece has the higher your level will be. Don't worry about getting matching pieces just focus on light. When you get your vanguard level up to two you can purchase legendary (purple) gear from at the tower that will have light lvl 33 gear.

Get your vanguard or crucible rep up and by legendary armour from the vendors

To level up further you need to obtain gear with higher light on it. You have blue gear and blue gear doesn't go any higher than 21 light. You'll need to grind out marks and some commendations (get these from leveling up factions once you hit level 3 with the faction). Buy all the gear from any vendor either crucible or vanguard and when Xur comes around buy an exotic piece of gear with strange coins. Level that gear up by doing bounties and you should be able to reach level 31.