It's essentially slang for a low-cost LED light marketed for growing. The "blurple" stands for the colours of most of these LEDs... blue and purple.
Your main job on the first grow is to keep the plants as healthy as possible, and reach the harvest finish line. The grows after that are where you focus attention on achieving higher yields, using the experience gained and mistakes learned in the first grow.
Subsequent grows will further push the desire for better quality, and higher yields with less work and less cost.