The benefits are primarily legal, privacy, and tax savings. At least in the USA.
1) As an individual you will be taxed "self-employment tax", which basically amounts to 15% that you have to pay in taxes. If your LLC issues dividends to you then you do not have to self-employment tax on that.
2) LLCs are less likely to be audited than Sole Proprietorships.
3) If your LLC is named your model name then people can just write a check to your model name. That means you don't need to give them your real name.
The disadvantages are that LLCs require a little bit of overhead and you will need to file 2 tax returns. You also need to understand how they work and there are steps that you need to take to maintain them.
In terms of the process, there are turn key company that will help you "incorporate" but I would recommend Michael Fattorosi (he's a lawyer that is well established in the adult industry and has worked with a lot of models). He can advise you and set up an LLC for you if it makes sense for your case.