I currently am a residential real estate agent acting as a sole proprietor.

I also recommend it for my small sole proprietor clients.

I'm a single member LLC so I'm treated like a sole proprietor per the IRS.

Applying for Your License There are no prelicense education, prelicense examination, or continuing education requirements for a limited broker's license, but you must apply for a business entity license (as an individual proprietor or some other type of business entity) and pay the associated fee.

Should an individual investor create a legal structure (sole proprietor, LLC, etc) before making that first deal or is it ok to engage in wholesaling solely as an individual investor; provided you maintain the proper records needed to file taxes to the IRS?

I propose a Tuesday night dinner at the Marshfield Tavern, 1 Proprietor's Drive, Marshfield.  

Fortunately, many business owners were doing business out of their "garages" as sole proprietors long before incorporating or forming their llc.

A sole proprietors or small firm would probably be your best bet. 

Sole Proprietor?

I have read everything from a trust that owns a holding company that owns an LLC for each property to just owning everything as a sole proprietor.