Hi Nick,
a big congratulations to you for making a start. I also purchased my first rental property at 19 using my parents house as equity (that was 14 years ago). My experience has been that 1 to 5 properties can be easy to manage by yourself even with a full time job. Apart from saving cash, the benefits of doing it yourself are that you learn how to manage tennants and learn what is involved in the rental industry. In years to come, as your number of rental properties increase, you may need to hand them over to a property manager and having previously managed them yourself means that you will know what to look for in a PM (some are really bad) and know how to manage the PM.

All the best
Xenia