You can check their insurance coverage, any active lawsuits they have, their workers comp rate (how safe they are on the job site), and other metrics.

Also, access to online HMLs is compressing the total returns as the market gets more efficient.

If you just want the knowledge, sure, take the online classes and tests.

I typically use regional banks to fund my deals but my 2 go-to banks have either slowed or fully stopped investment loans so recently I've connected with several online brokers but all came from ads or they reached out to me vs personal recommendations and intros so I have concerns. 

The more people you meet, the greater chance you will find new cash buyers.Online Lead Capture FormAnother way to find cash buyers is through online lead forms.

The online reviews are spotty.

Online title search companies.

Also from what I've read online breaking into the insurance side of things sounds like it requires cold calling and building relationships with those reps vs just registering property in database and waiting.

If you are newer and looking to find a safe place to learn and grow, he offers a great community of leaders wanting to help others.

Check out other online guides available here: https://www.biggerpockets.com/guides3.