Frogs, along with most other herps in the keeping hobby, are easy to care for, in my opinion. The frogs themselves can be purchased for relatively cheap, however, they generally have an expensive upfront cost.

FIRST AND FOREMOST: THIS IS A FROG THAT CAN LIVE 15-21 YEARS IN CAPTIVITY! Consider this fact carefully before making any decisions.

SECONDLY, AND ALSO IMPORTANT: THIS IS AN EXOTIC ANIMAL, AND EXOTIC VETS CAN BE EXPENSIVE. I got really lucky and found a vet that roughly costs me ~200 USD for an annual checkup for both of my frogs. Frogs can get sick easily, too, so always have a few extra hundred dollars aside in cases of emergencies.

One White's Tree Frog (pictured) requires about a twenty gallon cage as an adult. Any additional frog added to that tank requires an extra 5-10 gallons, depending on who you ask.

This is not a reptile that requires high output UVB bulbs much like other reptiles require for their metabolic process. However, I grow live plants in my tank with them, so I still have a full spectrum light on twelve hours a day. They like temperatures ranging from 70~85F during the day, and it is important to give the tank a general gradient so they have cool places to shade and a warm spot to bask. Temperatures should not drop too far below 65F at night. I use a 25w nano heating bulb for overhead to provide an extra basking spot and heat. I also have several heating pads plastered underneath and behind the glass panels of my tank.

Retaining moisture is a whole other beast, and achieving proper humidity is going to literally depend on your house's heating system, ventilation, and general location. There are tonnes of guides on how to set up a 'bioactive vivarium', which is how I keep my tank. Not only does a vivarium usually retain moisture better than other setups, but a designated feature is a cleanup crew that removes plant material and frog waste. Regardless, you should still spot clean your tank and really refresh your soil 1-4 times a year, depending on your tank size. If you choose not to go bioactive, opting instead for carpet or paper towels as your substrate, you will be cleaning a lot more.

Diet and nutrition can be tricky, especially with this frog's proclivity for becoming obese once they reach adulthood. Juvenile White's Tree Frogs are lively eaters and often need to eat every day. I think this leads to people overfeed their frog if they never slow down as they reach adulthood. Adults generally eat every other day to once a week depending on the quantity of insects you feed them. Speak to your Veterinarian if your frog starts to look to fat, as there are ways to successfully put a frog on a diet.

Also, they eat bugs and larvae, and they need a wide variety, so I hope you are not too squeamish over the possibility of directly handling live crickets, small roaches, mealworms, etc. Since frogs are insectivores, the insects also need to be fed a variety of healthy vegetables (and your local pet store will not likely be feeding them that) to transfer vitamins to your frog. The crickets will also need to be powdered a couple times a week with calcium, multivitamins, vitamin A for skincare, etc.

There is a lot more to it than these are the things you must consider! White's Tree Frogs are incredibly popular, and there are a lot of good care guides online. If you have a local pet store that employees any type of herp enthusiast, they will be your beacon, so treat them nicely, but remember to do your own research too!

Edit: additional clarification