Occasionally, they don't even have it then!

Occasionally there are some that don't ask 1000 questions and are pretty self sufficient, just trying to maximize their time and network, so those may get some consideration. 

Occasionally you will run across a listing that lists actual numbers.

I agree with Anson that a multi-unit would be great, and occasionally I see one that works for an owner occupier, but you could probably do just as well with a couple condos.  

If you're starting out and need a lower price point to get into a property, if you're not interested in maintaining mechanical or roofs, if you want managed costs (HOA's) versus the occasional big ticket cost (hot water heater fails), they can be a great option.  

My wife and I are very excited about this opportunity and we have decided that we want to focus on 2-4 unit multi-family investments with the occasional SFH for buy and hold purposes.

Sure I have strong opinions, and occasionally I am forcefully and publicly WRONG.

For me, the benefits that make it worth it are...1) Credibility with sellers, buyers etc.2) MLS access3) The option to list the occasional property if I want and earn extra cash through a comission4) Not having to rely on a realtor for  realtor related tasks like gaining access to properties for sale.

I fix and flip and occasionally hold and rent.

As I understand, all rents are considered to be part of your income, in a way or two, so if you live rent free with an occasional handyman work, i think that will work out best for you, being 23 & 21.