A lot of this advice is fucking with you.

Here's the proper thing to do:

Write a professional-sounding letter giving two weeks' notice. So if today is Oct 1, you give them your last day of work as Oct 15. In it, you can say something like "the job wasn't what I expected it to be; I don't see myself being satisfied in this job. I appreciate the opportunity to be employed at XYZ Employer, but I just don't think it will work out. My last day will be Oct 15, 2000." Then you work for two weeks if they want you that long, and if not, peace out no hard feelings. They might even give you a nice recommendation for a future job you are trying to get if you are really nice about everything.

Trust me, it's not like a friend, you can just leave after two days as long as you are professional about it, no one will harbor any bad feelings about it.