@Christopher Hutchings congrats on getting the ball rolling. Your Real Estate Attorney should be able to provide most of the information on what structure to look into based upon liability protection. This link goes to the general business formation page for Illinois https://www.cyberdriveillinois.com/departments/bus...
and this link goes to the specific instructions and information on the LLC portion. https://www.cyberdriveillinois.com/departments/bus...
Here is a blog post I recently wrote about LLCs and which entity to go with https://www.biggerpockets.com/blogs/5926/53215-que...
A CPAs cost will be determined by what you want that person to do for you. If you want a once a year paper pusher to file your taxes, you can surely find that. If you want someone who will be an advisor and be there to answer questions and educate you as you grow and work to become an adept investor, there are CPAs out there like that as well. Whatever the cost may be, you should get at least their fee if not more back in knowledge and tax savings.