Free flying any parrot has risks, and not minor ones either. We had a very experienced member who flew his Macaw several times a week for years. THe parrot was spooked by something unexpected, got disoriented and flew away, never to be seen again. The best place to free fly is an open space like scrub land, open for miles around. Free flying in spaces like a park or field are just asking for a problem. Not many folks live near enough to ideal free flight areas. Some people are lucky enough to have access to an ENCLOSED area , like a riding ring, large gym or warehouse, all places for free flight that are relatively safe; however parrots trained in that are then at risk to fly away if they get loose outdoors.
SHould you want to proceed, I would try to find a local parrot club or society and see if they have members who free fly and ask for lessons and training tips.
GOod luck!