Hi and welcome!

You won’t get any judgement from me and most here. The breeder selling them so very young on the other hand…

I’m just happy that you found your way here, are asking questions and want to give your little one it’s best life.
There is a lot of outdated and just plain wrong info out there and it’s difficult to know what’s right and what isn’t. The best place for correct husbandry guidelines is
https://chameleonacademy.com/chameleon-husbandry-program-getting-started-with-chameleons/ After you read thru all of that, then check out
https://chameleonacademy.com/panther-chameleon-care/
There are some critical things to have right immediately….
Correct uvb is a linear T5 fixture with either ReptiSun 5.0 or Arcadia 6%. The distance between light and basking area needs to be around 8-9”. This is the type you need.
https://www.pangeareptile.com/colle...r/products/arcadia-prot5-6-uvb-bulb-with-hood The only chain pet store that I know to sell T5s is PetSmart. Do get the 24” one.
Food needs to be the correct size. Tiny babies need fruit flies, bean beetles or pinhead crickets. He’ll need to be fed as much as he can eat, twice a day.
You’ll need supplements. Daily you’ll lightly dust with a phosphorus free calcium
without D3. You’ll also need a calcium with D3 and a multivitamin, each to be used one feeding every other week and alternating so that they aren’t given the same day. OR, you can get a combined D3 and multivitamin such as ReptiVite with D3 or Repashy calcium plus LoD, which will be used one feeding every other week.
Temps for babies need to be lower, around 78 with 80 at the max. You may not even need a basking light. If you do use one, you’ll want to raise it off the screen by at least a few inches. Babies screen walk upside down along the top and can easily get burned. At night it’s best to have a good drop in temps.
Humidity for panthers during the day is between 50-70%. I keep mine at the lower end.
You’ll need to provide lots of branches and plants (live ones are always best) - lots of little chameleon roads to travel and places to hide or take some shade.
Misting the plants for at least 2 minutes, 2-3 times a day will provide adequate drinking opportunities and allow the enclosure to dry out in between.
Of course there’s more, but I’ll let you read and learn from the links I’ve provided. Once you’ve read all, do ask as many questions as you need.