First, welcome to the site. Actually, its a play pen, and we youngsters romp at will, until mamma or one of the sitters walk in.........
I would suggest the following
Dont have your O-bit in the paper BEFORE you walk in. UPS has hired some employees that appear to be dead, but it is less and less likely now.
Show up sober. I know, for the "normal" person, this needs not to be said, but you never know.
Dont have drugs on your body at the interview. Again, we get all kinds.
Have a relatively clean criminal record. IT helps.
Take a shower at least the day or two before you show.
Clean shaven helps
Clean clothes as well.
IF applying for an automotive job, it helps to know the following
What a battery looks like. Where you would find a wheel nut. The difference between a wrench and socket. The difference between a steering wheel and a 5th wheel. Everything else, we can work with you on.
And that pretty much covers it. If you can make it into the room under your own power, not let your face hit the floor, and leave under your own power, I dont see a problem.
Best of luck.
d