Pet stores dont really have anyone that specializes in snakes. Also, the kit makes it seem like it has everything you need to get a snake. It doesnt have anything for humidity or regulation for the included heat pad (nor does it tell you that you need it).
Take 2 towels, spray them lightly with that water bottle and put them to the left and to the right of the lamp (make sure they dont touch the lamp just in case). Both your temps and humidity should go up, just make sure you monitor it because your lamp needs regulation too (a dimmer), but a 40w red bulb isnt nearly as dangerous as a unregulated heat pad. If the heat gets too high in the tank, slowly slide back the towels to open more screen space to let the extra heat leave.