CES is not open to the general public. You will have to register. You must be "affiliated" in someway to the consumer electronics industry.
You're required to have 2 forms of ID, a photo ID (driver's license, etc) and a business card (make your own). It can be anything like "consultant", "sales representative", etc., but must be related to the media industry:
AAA Media Services
John Doe
Sales
(555) 555 1234 email@email . com
I haven't been in a few years, but I used go all the time when I repped for JVC.