What are George's reactions and thoughts following the meeting with the violent Curley?

Following their first meeting, it is clear that George holds intense reactions and thoughts about Curley.

An element of confrontation defines how both George and Curley view one another.  When Curley starts to insist that Lennie speak, the tension is noticeable.  Steinbeck describes George as "cold" and "tense and motionless." Curley is ready for a fight, complete with "elbows bent."  Both men really dislike one another.

Some of George's reactions and thoughts speak to this....

Following their first meeting, it is clear that George holds intense reactions and thoughts about Curley.

An element of confrontation defines how both George and Curley view one another.  When Curley starts to insist that Lennie speak, the tension is noticeable.  Steinbeck describes George as "cold" and "tense and motionless." Curley is ready for a fight, complete with "elbows bent."  Both men really dislike one another.

Some of George's reactions and thoughts speak to this.  Upon Curley leaving, George wonders aloud "What the hell’s he got on his shoulder?"  This is furthered by George calling Curley a "punk" and that he is "gonna get hurt." Towards the end of Chapter 2, George is very direct in how he feels about Curley: “Ya know, Lennie, I’m scared I’m gonna tangle with that bastard myself. I hate his guts. Jesus Christ!"

To me, your question sounds like what would George feel and experience towards Curley.  I think that you probably want to focus on how George really does not like Curley.  Curley wants to showcase his strength and intimidation over George and Lennie.  George senses that Curley is entitled because he is the boss's son. There is clear antipathy between them.  As a result, George's feelings and actions would reflect confrontation.