Hi , there is a flame supervision device that sits in the burner,gets heated when the flame is lit then opens to full gas rate. If this probe is faulty or dirty then the oven won't stay alight. As the flame is yellow the burner most likely has some food that may have dropped onto the burner.
Clean the burner thouroughly (it can be taken out. B it should be done by a gas safe engineer
Hi, yes you can do that. What you are looking for is an even blue flame
I would Hoover first then lightly use a damp cloth. If the flame co!our doesn't improve then get an engineer out.