The number of DC Comics Lantern Corps varies depending on the storylines and continuities. But typically, you'll come across at least seven major ones like the Green, Red, Blue, Yellow, Orange, Indigo, and White Lantern Corps, each with its own unique characteristics and powers.
Sure, Teen Titans belongs to the DC Comics universe. They have had many adventures and storylines within the DC framework. DC Comics has developed and expanded the Teen Titans franchise over the years.
Well, in the Teen Titans Go world, Beastboy might tell Green Lantern a story that involves their unique powers. For example, he could be telling a story about how they overcame a powerful villain by using both his shape - shifting abilities and Green Lantern's power ring. It could also be a story about friendship, like how they supported each other during a tough time in the Titans Tower.