I just got a part time job and no specific hour agreed between my boss and myself. On the ad, it mentioned about 20-40 hours a week though. After four days on the job, on the fifth day, I boss called and told me no need to go in for the day. (It was fine with me since it was a Friday.) The following Monday, when I walked in, he told me, there is some issue, and he will call me to let me know when to return to work. I asked him about how long, he replied, maybe two weeks. I am afriad that he is trying to get rid of me... anything I can do to protect myself?

If you aren't in a Union... or on an employment contract, you are what's called an "at will" employee. That means they don't NEED a reason to get rid of you... and you are also free to leave when you want. That applies the same for full time as well as part time.

Want to protect yourself?. start putting resumes out and look for a new job now. The writing isn't just on the wall, they read it out loud to you.