To play on Tamatown, you go to Tamatown.com, scroll to the bottom, click the little arrow, and then click what version you have. Depending on it, it will tell you to enter a code from your tamagotchi, which you choose by going to the connect icon and clicking PC. Hope this helped!
Ps- just for future reference, this should probably either be posted in what's on your mind or help for new Tamagotchi owners. Just sayin!