From my professional career development point of view was amazing. I was completely free to choose the project that I would like to lead, where I wanted to work if I wanted to travel or not.
Became a freelance is an exciting experience, BUT (there is a but in capital letters), you should manage properly your income and your mind, because maybe you will not work for 12 months a year and you should plan what you will do during your "free" time.
In order to start, I recommend you to contact local or global companies that provide Project Managers to the clients.