How do the Socs act and what is their gang "code"? How do the Greasers act and how do they stick together?
The Socs are superficial, privileged individuals who enjoy their material possessions and like to have parties. They also enjoy fighting the Greasers and picking on kids who are not wealthy. Cherry mentions to Pony that the Socs are pretentious and fake. Socs are more concerned with their appearance and status than they are with developing authentic relationships. Similar to the Greasers, their "code" would be to stick up for one another. For example, the Socs are quick to retaliate after Bob Sheldon is murdered and seek to avenge his death.
The Greaser gang consists of troubled youths who have difficult home lives. They enjoy hanging out, committing petty crimes, and fighting Socs. They are extremely loyal to one another and selflessly help each other when they are in difficult situations. Darry gives them a place to stay if any of them get kicked out of their homes, and each member is willing to fight in order to protect another Greaser. Unlike the Socs, the Greasers have authentic relationships and value each other on an individual level.
In my opinion, both of these gangs have a similar code. Their code is that they stick together and protect one another from anything that is not part of their gang. They both serve as family for their members.
You can say that the Socs act more aggressively than the Greasers. They seem to be the ones who go out looking for trouble. But this may just be because it is a Greaser who is telling the story. Clearly, the Socs try to protect each other, like when a group of them wants to fight Pony because he was involved in killing Bob.
The Greasers also stick together and protect each other. You can see examples in the time that they save Pony from the Socs and when Dally helps Pony and Johnny get away after they kill Bob.