In my opinion, you should setup the LLC before you do your first deal unless you finish your first deal before you finish getting your LLC setup. In other words, you should do both, and one shouldn't be a roadblock to doing the other. It's OK to pursue two things in parallel.
It doesn't take long to setup an LLC, so, if you're concerned about asset protection or about doing something illegal without the protection of a business entity, then wait 'til you have your business in place.
