Good luck with Petsmart. They have an online application program and it is difficult to get a job there. I filled out a few applications (petsmart, petco, pet supermarket) and never heard back from them.
Sadly the horse industry is a tough industry to get into. I used to work for the barn manager and she put in a LOT of hours. They had 30 horses and only wanted 2 people to work for them. They needed more employees, but wouldn't hire them!
I don't think she made enough. One year a horse she was working with kicked her and broke her ribs. I got trampled within a year of working there and quit. Walked away with a very sprained ankle. It isn't worth getting hurt for a job that doesn't cover your health insurance.
The girl who worked there before me was viciously attacked by their stud- he ripped her face up and they had to send her to the hospital. I'm not sure if she had broken bones or not, but her injuries were very serious and I wouldn't be surprised if she had some permanent damage to her face.
Right now I am feeding for a barn. I get $30 to drive there and feed. I got there the other day and their horse was severely colicing. Had to have the vet up- he was so sick he couldn't stay on his feet, and ran the vet's stuff over twice, nearly ran us over. It was very scary! We had to get him out of the barn to put him down and trying to walk him out took almost an hour as he was bumping into things. It would have been VERY easy to get hurt with a horse like that.
There are going to be other horror stories in the horse industry- people beat their horses, treat them like trash, drug them up for shows, leave them in stalls til they are mentally damaged. If you train and sell, those horses can and will end up in bad homes. Trainers lose their tempers and beat on the horses they are training.. Or you have to call the police for neglect cases- "that horse kicked my friend so I'm not going to pay for it's farrier" despite the fact the horse is a week away from foundering (if not already)...
It is not a "Fun" industry to be involved in. I have loved horses my entire life, but I am burned out on working in this industry. Everything I have listed here are things I have seen.
My advice: Get a high paying job, save up all your money, buy a property with acreage and have your own farm. That way you can control what horses you have on the property, who works for you, and how that barn is managed.
Carpal tunnel (from mucking stalls) is not fun to live with.
My only other suggestion if you love working with animals is to work with a small animal vet or as a small animal groomer. Safer and the pay is better than doing stalls. Decent enough for a starter job. You may need to do volunteer work first to get experience.
If I could do it all over, I would have picked a different career. Too much heartbreak in the horse industry. It is not easy to switch jobs if you find out your boss or other employees don't treat the horses right. Not when you have bills to pay.