Once you have acquired a small sum of coins, you can now begin using them to buy various goods and services, as long as they're accepting the cryptocurrency you have chosen. This done usually by simply scanning a QR code if you aren't on your PC or simply copying their wallet address and sending coins directly to their wallet. There usually isn't a transaction fee, but it is usually around the equivalent of $0.05 USD in your coin of choice if there is one.
There are thousands of businesses accepting cryptocurrency because of how fast it has been growing and they see the potential for it to become a staple currency. Some of the more popular websites such as eBay, Paypal, and Zynga are just a few examples of big names that are getting involved.