Congrats on taking the first step!!
As far as eating don’t go in on an empty stomach. A lot of testing centers don’t allow beverages or stuff in, so take a sip before you go in, but don’t guzzle. Using the restroom beforehand also isn’t a bad idea.
I’d bring/wear an extra shirt, jacket or something so that you can remain comfortable if it’s hot you can take it off, cold, keep it on. You get the picture. A lot of people don’t care, some people do. It’s pretty much preference. You’ll have to find what works best for you on a lot of this “pre test” stuff.
I usually get to my place early and spend a couple minutes doing some last second overview.
The test center already told you this probably, but you’ll need 2 forms of ID (one with a picture) and your SSN. Also, make sure you payment ready to go (for example, my test center will only accept a check or money order, no cash. Find this out!). For the test itself you’ll use a CC.
NOTE: Unless you’re already enrolled in a college, BEFORE the test itself, select “Score Recipient not listed”.
NOTE: At the END of the test, it will ask you if you want to send your scores. Hit YES, or Confirm or whatever it is (can’t quite recall). YOU WANT TO SEE WHAT YOU SCORED. Whether you see them or not makes no difference.
Go in with confidence, and tell us how you did! Good luck!
EDIT: I remembered this link and you may want to check it out.
Test Taking Tips and Strategies - Free-Prep-Clep.com