RULE #1: Your personal safety comes first.
You cannot help a parrot if you get into trouble. Trained volunteers are always needed--but the untrained will be turned away.
You may be a barista, or a gardener or a CEO, but you may find yourself in a disaster trying to help injured wild parrots.You probably have no experience with handling parrots. The best way to prepare in advance for psittacine victims is to make contact (and volunteer!) with local wildlife carers or rescue organizations, which even in non-crisis times is valuable and mutually beneficial. They may need your assistance on many levels, even in normal times. Local Animal Disaster Teams have regular training sessions and team exercises. Check with local Humane Societies, shelters and law enforcement offices for details. Trained Volunteers are ALWAYS needed!
It is very important to be familiar with the laws governing wildlife interactions within the country. In some areas, even benign assistance to injured psittacines may be an actionable offense. Making friends and securing professional bridges with local authorities will go a long way in the event of a catastrophe.
Gaining experience with psittacine restraint, capture, examination, and care could mean life-or-death in the field. It is well worth finding wildlife rehabilitators, avian-experienced veterinarians, and and others willing to train you on these skills. Finding out who and where local animal disaster planning organizations and their civilian teams operate is a great start.
The only way to REALLY know how to work with wild parrots comes from doing it, many times, in real life.