That is something that I've thought about many times 
There are a whole lot of reasons I don't think I could do it - maybe a few of them will help you out? Also, I had a bunch of other ideas if you want to be an entrepeneur...
1. Owning your own petshop would make you, as I've already said, and entrepeneur. This CAN BE a very rewarding and lucritive thing to do, but you have to be very good at it. I'm not saying you wouldn't be - but consider the business you have to know. If your shop gets big, you will have to hire and manage employees and manage bills. When you're first starting, ends won't quite meet. A business loan will get you started, but it's a huge risk - if your business does not do well, you're in a whole lot of debt!
2. Would you be selling live animals, or just supplies? I can see the temptation to start a petstore that sells live animals, but gives out correct information. Unfortunately, there are a couple of problems with that. The first is that some people will not buy a high-maintenance animal after learning that it is high maintenance - great for the animal, but bad for business. Another is that you'd be contributing to the problem of unwanted animals. But the one that bothered me the most was not knowing what kinds of homes these animals were going home to. I'm sure you know: you can talk and talk till you're blue in the face, but some people are just stubborn and will do whatever they want, anyway. As an alternative, you could sell just supplies, but that creates problems, too. A large percentage of people with pets - particualarly birds and exotics - buy them from petstores. Those people are more likely to return to the store they bought there pet to stock up on supplies. Another alternative might be to coordinate adoption and education days with animal rescues and humane societies so you're actually helping fix the surplus problem rather than contributing to it.
Here are some ideas that I came up with for working in the animal industry. I don't know what other animals interest you, but there are a lot of options!:
PET CARE:
1. Veterinary Technician - it sounds like you're not into the college thing. I can appreciate that, believe me. Some vets will hire technicians with no experience and then train them. You might have to start at the bottom, though, by cleaning kennels and whatnot. Veterinary technicians help administer medication, give immunizations, surgeries, and other veterinary procedures.
2. Groomer. There are many kinds of pet groomers - not just for dogs anymore! There are groomers who specialize in horses, dogs, cats and even birds!
3. Pet Day Care. This involves a bit of entrepeneurship, too, but to a lesser extent IMO. You're basically just babysitting other peoples' pets, but at your own facility. You can set yourself up for whatever kind of pets you'd like to specialize in - including iguanas, although it might be harder.
4. Speaker. I don't know what you need to get started, but places like schools and clubs hire speakers to come in to talk about wild animals and petcare.
ZOOLOGICAL
There are also many careers available in zoos and aviaries. You'd be surprised at how easy they can be to get into. It's easier if you have a degree, but you CAN work your way in from the bottom. It's hard to start from the bottom - I'm in the middle of doing that myself - but it can be done. I'm interested in education through animal training, but there are lots of areas. Day camps are becoming more popular, and zoos are always looking for counselors. There are opportunities in herpeculture and aviculture especially, since more people go for the mammals. If you want to work your way in from the bottom, a good way to start is by volunteering.
I've done a TON of research on this topic, so if you have anymore questions or want help, let me know!
Alika
