Looking for tenant procurement service only.

Also included on the list of activities that require a license are any attempts to lease property, any acts directed at procuring tenants for a property, the negotiation of leases, or advertising or holding oneself out as in the business of leasing property.

As for whether you'd be responsible to take out a loan if an investor puts 20% down; unless you have another means of procuring the other 80% - yes. 

In Nashville, where my other properties are located the typical management fee is as mentioned 8-10% of gross rents, however, what I do see a lot of variation in is the "lease fee" the percent of the first months rent to procure the tenant.

Then they might even feel entitled to a procurement fee anywhere from 100-half a month rent to a whole month's rent or more in some areas. 

In fact, I would generally avoid most multi-units in South Florida unless YOU are the procuring buyer.

You also do not want to have the listing agent show you the property, thus becoming the procuring cause of the sale and then have your current agent jump into the picture.

However, the agent has exclusive right to sell (whether he procure the buyer or not, he's entitled in comission).

Procuring cause.

Once you do decide to procure your first rental, definitely lean on the BiggerPockets community as a resource; I'll also say that it could be worth considering a shot at a software solution built for DIY landlords (1 - 15 units) to bring some automation to the rental management process (just to make things much much easier for you)!