A guy who is 6 months younger than me said that "You are old." Then I was quiet. It was because I like him. He changed his tone that "Actually you are very young, just 5 months older than me." I was still quiet and smiled in response to him.
Does he like me? If not, he doesn't have to appoint me for tomorrow's evening's movie and hang out with me every day. If he does, why does he just want to meet me 15 minutes before the movie on a Friday? He wants to walk with me around park for an afternoon, but not to want to go out of campus with me.
On the way back home, he said "You seem very quiet, did I make any mistakes?"

I called him once to tell him that I like him. The other day he didn't say anything about it, but he didn't make me feel embarrassing because he spent much time with me after that. What is he thinking? What should I do?

Just be yourself and do not go overboard with telling him you like him because that tends to scare some guys off.