Why are my dash and tail lights not working?

It would always be good to list what checks you have done, so others know what is left to check or test.

Having said that, …

Did you test the fuse for the dash and tail lights? - simply use the same kind of fuse from another slot and see if that fixes the dash/tail lights. If that switching of fuses works, its the fuse.

Unless you had a serious accident that can damage wiring and connections, test the connection to the tail lights. If you know how, see if that connection works. If it works, it is not a wiring issue.

Then it could be the On/Off switch on the dash that works for both the dash lights and the tail lights. The switch is worn out, broken, shorted, etc that will not turn on the dash/tail lights. Test the switch if you know how.