There is no 'school' to go to....best thing to do is just start studying.....I would get your RE license just to know the language and law.

straightforward to get my license as in studying for a month or two then taking a huge exam?

If your goal is to be a real estate investor, then I highly recommend you learn/study/live an actual RE investing strategy like buy and hold (which can be straight landlording, house hacking, BRRRR) and can be done in single family or multi family or you can flip or develop properties (but that too is a job and income stops when you stop flipping).Not to discourage you from your wholesaling desires, but think long and hard as to how and why you came to such a decision and know it is NOT RE investing.

Needless to say, I'm beyond excited to learn more, figure out the process, gain confidence, find a core 4, learn more, study more, and I feel that the wheels are finally on track and I have direction and purpose.

With the very limited information you provided and the way you presented it, you made it sounds like you were just jumping in and buying land without actually doing any feasibility studies. 

When we took it over we discovered the entire building was infested with bedbugs so badly that our bed bug remediation said if this had happened before heat treatment was introduced the building would have probably been torn down.

Cost segregation can find more deductible items in your property, but full cost seg study on a $390k house is probably not worth it.

I would also try to discover if the basement was finished by a licensed professional vs a rookie who doesn't know the ins and outs of DIY.

If it's truly valued at $400k, you could pull out up to $300k with no tax implications whatsoever (you'd be taking on debt, not incurring a capital gain).With regards to depreciation, engage a great CPA who understand and specializes in real estate investing, and ask them if it's possible to use a cost segregation study to take accelerated depreciation.

Is there a single comprehensive book/resource which could be a good bible to learn from/study?