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.  

Who has the best reputation in Cedar Rapids, Iowa?

I grew up in areas like these and I know first hand there are good people in those areas and unfortunate they just dont make enough to be in A class areas its not to say you cant make money in those areas because you can and attract the right people and for your noble deeds you done will build your reputation around the area where people will be beating down your door to rent and even would want to buy a property from you.

Called reputable property managers in the area and told them I was looking at a specific size/class of building and got their estimates on what it would take to run the building.