Black pants and a dress shirt
Business, no cut jeans or sweats, hide your tatoos, modest amount of jewelry, leave most of it home... smile, offer a hand shake, walk right up to the reception desk, say what you are there for and ask to see HR. Bring a recent resume, guard and driver's licence, a passport is an asset if you have one.
Nice slacks in navy blue or black and a nice shirt like a clean cut golf or Polo shirt (light blue is a good choice as you will already look like you belong with the company) with closed toe dress shoes or good condition work boots.
(Female) I wore a dress with a black blazer and flats and it was well received!
Shoes and slacks with a blazer
Appears with smart clothes, very neat and well iron