It had some settlement issues but the sellers and my agent had already done the leg work for a quote on the rehab with a very reputable company.

I joined Keller Williams because of the reputation for their training for new agents.

I would connect with a couple of local reputable Realtors and commercial brokers in the markets you wish to pursue.  

However, based on your description of the type of tenant you had, the city (Revere), and it's well deserved reputation (going on decades), it's likely not in a good area. 

I use Sherman Bridge but Lima One, etc. are all reputable.

I'm sorry this happened to you - and now is an opportunity to set your reputation in that market as someone who will not be victimized. 

You need to know with deep knowledge the following:*Establishing ARVs* Estimating Repairs with a reasonable level of accuracy* Finding and vetting buyers, so you don't hang a seller out* Learning to efficiently market for properties and how to close those leads* Establishing a good reputation with buyers, so your business can scale. to name a few...If you put an effort in and ask intelligent questions, you will find more than enough people willing to answer your questions, and they won't send you an invoice for it.Don't come in asking "teach me everything you know", without showing you have put some effort into it, initially. 

Are there any classes, videos, etc. that are reputable and designed for people with more to invest? 

Remember though, a good reputable PM will be interviewing you as well to ensure you match with them.I see a lot of investors look at their PM as their "employee" and they are in charge, and these are the types of arrangements I see fail more often than not. 

Make sure you find an experienced and reputable wholesaler.