Are there any local meet ups or websites on where to find more people who have a moderate level of experience meaning they are  somewhat experienced but still looking to collaborate and network with more inexperienced investors like myself.

Do you sell / buy real estate in Mexico personally? 

Personally, I wouldn't offer SubTo or a Wrap, For reasons I've written about fairly extensively. https://www.biggerpockets.com/forums/70/topics/1227199-the-m...However, I would sell on "Lease Option" and that may work for you.

Tell me - someone selling their home to your son, Subject-To - is this a person who has made good life choices? 

Major Development Projects Shaping Louisville’s Real Estate MarketLouisville and its surrounding region are experiencing a wave of significant development projects.

Would even be happy to meet in person since we are in the same area.

I was thinking if I can talk to my neighbor about sharing the cost (I, the landlord, personally provide labor and my neighbor provide material (e.g. fence pickets)).

I have personally used the BRRRR strategy over 40 tiems my self in Memphis.

A contract is only as good as the person enforcing it.

CPAs generally have more knowledge about general accounting but it is ultimately up to the individual person to take it a step farther to get more specialized.