As @Hai Loc wrote, there are several "big box commercial brokerages" which publish average cap rates, per assets class, per city.

I quit my full time accounting job at the beginning of this year to focus full time on real estate and my mortgage brokerage, and I’m not looking back. 

As I read Finding and Funding Great Deals, there is so much valuable info and I realize I would like to have a Broker/Agent mentor with similar experience.

Keep looking until you find a brokerage/website that has hundreds of positive reviews--they are out there, it just takes some effort.When you find a company, use search terms "[company name] reviews."

Have offices  back end support staff.. sales teams ( closers) etc etc etc.. just like starting any real estate brokerage.. which is essence is what your doing.. 

Would anybody recommend a brokerage or realtor that know about which apartment complexes are for sale?

, and I am currently looking for a brokerage to sponsor/hang my license. 

To be a Property Manager (for other people under a brokerage) you need a license with 2 or 3 years of RE experience.  

I learned a lot also just from spending time in the office (my class was held in a brokerage) and chatting with agents about things.

I've been building up my brokerage account with Robinhood for the 3 years I've been in the workforce along with funding retirement and savings accounts.