Hello and welcome to FF Michelle! Here is a link to a great article on White's: Frog Forum - White's Tree Frog Care - Litoria caerulea. In the case of these frogs, humidity is less important than good air circulation and anything between 50-65% should do, as long as Loki has access to a daily cleaned dechlorinated water bath. The 85F basking spot to sleep under is a necessity too.
Gut load the frogs insects with fresh veggies (carrots and lettuce) and cereals (oats and cherios) and remember to dust food with supplements and all should be OK with Loki. Good luck!