How to become an animal trainer/handler? Please read all!?

You talk to those already IN the kind of job that you want. So whoever is doing this at theme parks or events are your best bet. Join some of the parrot and reptile forums on YahooGroups. Check with the rescues for both those creatures.

It's going to be a very small job field though, you understand, so I would do all I could to get cross training in other lines that would parallel that. Most of which will involve volunteer work. If you're in a large city, check with your local shelters and rescues. It's experience that counts. It won't be a field, though, that will bring in enough money to live on comfortably. Having a 'day job' will be key to following your interest as a trainer/handler on your own time afterwards.

Be aware that you can supplement this interest by WRITING about it, if you have writing skills. As articles or short stories or even a full book for publication.

If you can find a used copy on Amazon of 101 Best Businesses For Pet Lovers, get it, it's got some good ideas in it.

There are online links you can check ----
https://www.glassdoor.com/Salaries/animal-trainer-salary-SRCH_KO0,14.htm
https://www.salaryexpert.com/salary/job/bird-keeper/united-states
http://betterwords.typepad.com/birdvice/2009/01/careers-in-birds.html

Wild animal trainers are about a thing of the past, just no call for them.
Sanctuaries may need animal caretakers though, and at leas a matter of demonstrating 1000 hours background with animals.
Courses in animal sciences can get you a degree working with animals or pursue courses in animal biology.
I got fascinated with bats years back and did my own studies. With the help of some college chiropterologist, managed to show 1000 hours working with bats and that got me a county wildlife rescue/rehab license. Texas has a huge bat sanctuary I would love to be part of.