The psychological benefit of an LLC and an e-mail
In my book, my general philosophy towards administrative stuff is to do as little as possible and only after you've taken care of the important steps first (figuring out your 1099 rate, implementing a strategy to get your first gig, etc.).
While I do think you should register an LLC, it's not strictly necessary, and you can probably get away with not doing it at all.
That being said, one non-trivial benefit you may get from registering an LLC right away is that it creates a psychological separation between yourself and your business.
Dale the person may feel weird about aggressively negotiating with a program manager for a higher rate, but Dale LLC knows it's just part of doing business.
Dale may feel weird using his gmail.com e-mail to reach out to cold contacts, but firstname.lastname@example.org has no qualms about setting up coffee meetings with business strangers.
It doesn't actually take long and isn't too costly to set up an LLC (maybe $100-$200 for the LLC registration and $6/month for an email) so if it helps you feel more confident about going 1099 and less amateurish, go for it.