If you provide photos of the animals and keep up good communication with your customer, you shouldn't have too many problems making sales, and then you've started building a reputation. :-)

Like above said, connect your paypal to a bank account or credit card, and then others can send it to your paypal account - which sits in your account and you can withdraw into your bank (or use to pay for other things online).

There's a subforum here on shipping questions and I know a lot of breeders use shipyourreptiles.com which means you don't need to start a fedex account. As for the government, no, you can sell a low-medium volume of animals without being taxed and whatnot - if you ever make it a real business, you need to go through some legal steps, which is actually beneficial if you sell a lot of animals because you get tax breaks and are treated as a corporation, not a person.

Good luck!