Pull out the bottom drawer and tell me if the Glow Coil comes on
Try and push the bake and then 350 deg .
Check the glow coil see if it comes on or not and what the timer does
Does the temp go down to 100 deg
Well the only way to find out where the problem is .
You will need to get a volt meter to check to see if you have voltage the the Glow Coil.
It could be the timer but then maybe not the meter is the only way.
You can take it out and look at it the Glow Coil