If you took a phone and plugged it into the jack on the outside Network Interface (NID), and you found dial tone, then there is a problem inside your home. Either the problem is with the wiring or a phone device (ans machine, phone, fax) connected to a jack.
If you want to try to isolate it yourself,
1. Disconnect everything.
2. Take a corded (not a wireless phone) and plug it in to each jack to see if there is dial tone. One jack at a time.
If you don't get dialtone at any jacks, then you may need Vz help.
If you get dialtone at some jacks but not others, then you have isolated the trouble jack(s). You may want to open each jack in the line and make sure there are no wires touching each other.
If you get dialtone on all jacks, the plug in all of the other phone devices one a time, (leaving each previous device connected). Once you connect a device and the dialtone goes away, you know the problem item.
If none of this helps, then call 1 800 Verizon, in the voice response system make sure you confirm you telephone number and say phone tech support or repair.
The copper repair agent should be able to test your line. If you have an inside wire maintenance plan, then Vz will send a technician to diagnose and fix the inside wire problem. If you don't have inside wire maintenance, there will be a fee. The repair agent should be able to tell you what the fee will be.
Hope this helps.