Cn anyone help? I have fitted a new cable and my speedo is still not working! Please help a damsel in distress!!!!

It’s probably the little plastic bit that fits over the sprocket nut to drive the cable. They can round off.
Pull the sprocket cover off and have a look. You can get new ones from Graeme France or David Silver.
Also lube the mechanism the cable goes into on the sprocket cover

The inner cable rotates as the rear wheel turns.
Support the back of the bike on a stand.
Disconnect the cable from the speedo.
Rotate the rear wheel.
If the inner cable is rotating you have a speedo problem.
If the inner cable is not rotating you have a drive problem, see previous post.