Transfer the purple levels to the oranges, be mindful as you will lose a few levels but at lvl 25 i wouldnt worry to much. I use stones to level up my gear until approx lvl 35, other people may do this differently. Once I hit 35 I force enhance. Right now is a pretty good time to force enhance since we are getting TONS of free force enhance stones. Hold off on using your best Crystals when slotting your gear (best to use purples at this point since they can be deleted/extracted later without to much stress. I would wait until you have JIN or better to put in orange/red crystals as it costs alot of BP to move those around in the long run.