Had my first day of work yesterday, feeling disappointed?

Well, I'm a bagger/go backer. I thought this job would be easy as pie, but it was so hard. This is my first job and the first 'real' work I've ever done. I worked for six hours yesterday and now I have aches all over. I never got any training on what to bag or how to bag. I found it hard to put all the heavy stuff on the bottom to put the fragile stuff on the top, because all of the fragile stuff was being put first and I don't have enough room to sort it all out or even enough time. I'm so mad at myself and I complained all day yesterday. Please if there are any baggers out there, did you have a hard time too? ://///