New to Zwift... not working :(

Just joined Zwift, got new Wahoo speed and cadence sensors for winter training, running on a mag trainer.
Zwift has paired the sensors ok, but when I try pedalling on a route, I just sit there on the screen …

How is your speed sensor attached to your bike?

I just finished a ride.
The site is up and running well.
Usually, most problems are do to a local issue.
Make sure the batteries in your sensors are good, make sure the sensor is detecting the magnet.
Usually there is a soft “beep”.
Make sure the program is detecting your sensors either with Blue tooth or Ant+.
Ant+ seems to be the most hassle-free but usually requires a dongle.
If you have a dongle, use a USB extension cord to get the dongle closer to the sensors.
If you you blur tooth, make sure the sensor has not inadvertently paired to another device because then it wont be available to pair with Zwift.

Stick with it and stay calm and logical and you will work it out.
Every day tens of thousands of people Zwift and everyone of us have a slightly different set up.
We all have to work thru it and once we have a set up that works, we stay with it.