What you do is pay the $5 marketplace fee and post pics and prices of your discs on the marketplace. If someone is interested they will PM you and you discuss the purchase/trade of discs. Then you give them your paypal info or vice versa and you exchange monies. Whoever is the seller then mails out the discs. After the disc is received they will give you feedback for the transaction.
I do that also on a regular basis. I have been getting better with the backhand snap and have gained more distance. It is starting to come together. I have been lucky because I recently found 4 drivers (3 had no contact info). So I now have plenty to practice with
To help you out, let me suggest that you spend a few hours a week throwing in an open field. Learn excatly how far you are throwing each disc, and practice throwing left, right, and straight. It will help you alot. I have been playing for 5 years, and I still spend time once a week throwing in an open field