You're doing the right thing by coming here and asking questions, thanks for that!

It sounds like you're using a 'critter keeper' type of enclosure? That might be a little on the large side. A rubbermaid shoe box will do (and you can save a bit of money too), you should find plenty of examples on here of how to set it up. Use a UTH or flexwatt, and don't skimp on the thermostat.