Some plpt details From a test screening. Not TOO spoilery;
-The High Evolutionary is the charismatic leader of a intergalactic space organization. Think like Stark industries in space. However, his company conducts many horrific experiments behind the scenes. Young Rocket was one of them.
-Adam Warlock acts like a big dumb baby because he was just born and only listen to his mom. He's also unaware how much damage he causes and how truly powerful he is.
-His mom sent him to kill the GotG. They get away but Rocket is hurt badly. Most of the film they are trying to break to High Evolutionary's (Rocket's creator) lab to find the means to heal Rocket.