Confused about the job search

Hey guys,

I'm currently in university and have just begun searching for a summer job. I have created a resume and went to a few job fairs and haven't had any call backs.
This leads me to think that I might be presenting myself wrong to recruiters and hiring managers.

Next week I'm going to be going to the mall and handing out a bunch of resumes to try and get an interview. I am specifically looking for jobs where I can get customer service and retail experience.

Anyway my question is: how should I go about applying for jobs at the mall?

Should I just introduce myself, tell them I'm looking for a job and then give my resume and be off?
Also is it true that its better to apply in the morning rather than after lunch?

Thanks!!