It's great to have you here.Here are some recommendations for you:Find and connect with other BP members that are in your area: http://www.biggerpockets.com/m...Set up keyword alerts to be notified of the topics that interest you: http://www.biggerpockets.com/a...Read Beginner’s Guide: http://www.biggerpockets.com/r...Check out BP Money Podcast: https://www.biggerpockets.com/..Wishing you the best

Check out some local meetups in your area to connect with more investors.  

She paid in full Wednesday but asked me if I would wait to cash the check for a couple days. 

Should I also run the credit report and background check on the co-signers?

I have.Does a PM check on a tenant that didn't show up for work and find him unconscious and unresponsive and call EMS?

One of my clients recently purchased a home in Big Bear for STR and I understand it's going pretty well.Best site to check numbers is directly on Airbnb.

Check out some local meetup groups in the area.OCREIN - Unlock Your Real Estate Success: Stand Up and Connect!

Also check out platforms such as "Meetups" or "Eventbrite" if you haven't already.

for $40 it only gives a "rating" and no specifics.is there a service of reasonable cost that actually give me a credit report and details on results of background checks?

I'm not surprised, but checking ID is one thing.