Keep Doing Heroic Strikes
The recommended light level for the raid in Destiny: Rise of Iron is 370, though you can easily jump in and get through it with the help of a coordinated team from 360 light and above. However, if you want to get the highest light level possible before doing the raid, the best way to get yourself past that 365 threshold is by completing Strikes in the Heroic playlist. Once you’ve hit 350 light, start doing Heroic Strikes and infuse all the blue drops into your purple gear to bring your level up. By the time you hit 365, you’ll realize that the only pieces of gear holding you back from going higher are your Ghost and Artifact, and that’s because there are no specific engrams for either of these items.
This is mostly RNG-based, but keep in mind that Strike bosses have a chance of dropping Ghosts and Artifacts, along with other blue gear once you defeat them. Do make sure that you’ve equipped all of your highest light gear though; that way, you’ll get better drops with light values two or three points higher than your current level.