You recently exchanged your Blackberry Tour for a Droid Incredible. You can't get your calendar from Yahoo to sync with your Droid. Both have Verizon Wireless service.
You have tried moving your Yahoo calendar to Google. You can't even get a Google calendar to sync with your Droid. When you get an Android phone, first thing you have to do is sign into your Gmail account with your phone.
When you've signed in, it begins a process of syncing your Gmail, Gcal calendar, and contacts to your phone for first time. It takes about 5 minutes depending on how many messages, calendar items, and contacts you have. If you have more than one google account, you'll have to decide which account you want directly connected to your phone.
Please use your Android's Gmail application to access your Gmail account. If you use an HTC mail application, it won't let you sign in without some additional configuration. That HTC mail application I think is designed for accessing other POP email accounts ie. Hotmail, Yahoo, or mail on an exchange server.