I wouldn't ask them any more questions if that's the info they gave you. You should dive into past threads here and learn what your snake needs.
The snakes don't need light, they need the heat which comes from the light bulb. You can use a red bulb 24/7 if you like. The snakes doesn't care.
You can use other heat sources but it does not seem like the other options are going to work well for you right now. Those would be things like a oil filled heater or rhp.
A uth does nothing for your air temp. You need to make sure the air temp is within the proper range. I shoot for 77-84. As long as it is within range that will be fine for your snake. 75-88 will work but I prefer my range.
What is the temp in the tub?
What is the room temp?