I raced on a one-day license (bought the day of the event) for my first race, so I could get my feet wet without being $60 in the hole.

A one-mile loop criterium is going to be a hard fast race emphasizing bike handling skills, especially cornering, and the ability to conserve strength by accelerating with the pack. Especially if there are no hills to break things up, it's going to be about power-power-power and not crashing. But a lot of people find them terribly thrilling with the adrenaline rush and the fact that being bullheaded and aggressive and riding that fine line between daring and foolhardy will be the factor that wins you a race!

If you never have a first race, you'll never have a second so yeah, I say go for it and jump in!

If you can, practice your group riding skills (especially pacelines, drafting, and cornering in close proximity) as much as possible, and try to grab some more experienced folks to give you tips. My racing pals have been invaluable. Good luck! (I just took second in my third ever race, and am looking forward to my fourth this coming weekend!)