You can buy, hold and sell properties in an LLC for yourself. When you start to deal with other parties and acting as a Real Estate licensee then you need a license. If you have a licensed person do the selling for you etc then you would not need to be licensed.
Example, you can go out as an individual (or LLC) and buy properties all day long. As an individual you can be a FSBO with your own properties and not be licensed. As an individual you can hire a licensed person to act for you and be completely legal as well.
When you start to assist others you then cross over quickly into needing a license.
I'm not exactly sure what you want to do? Are you more interested in the buy and sell or being a Realtor?
I think I confused myself tonight! HA
Arizona Homes for Sale by a Guy from Iowa
Hopefully others will contribute and help you out as well.