Easiest is contact property management stating you want to hang your sales license under their insurance, broker license and work PT. You give him a split and possibly learn about their operations. You should be able to strike on your own manage properties and decide you want to do it FT or on your own.
There seems to be a lack of property managers for small multi-fams. At least in my area of South orange nj. I have a quadplex that I’m looking to get managed and most won’t give the time of day for such a small portfolio. Could be an exploitable niche.
@Troy Weygandt I think the best option is to find a property management job with a property management company. That provides you with a paid position, training, expertise, forms, policies and procedures, etc. You can learn the business quickly and decide if it's right for you. After some time, you can break out and start your own PM company.