Newbie questions!

Hi everyone! Im new to the beardie world, but I had leopard geckos for years, so I'm not totally new to reptiles. I don't currently have a beardie, I'm just working on the proper setup and want to get temps right before I get my dragon.
I do have few questions though:

This is the tank I'm looking at
https://www.petsmart.com/reptile/habitats-and-decor/terrariums/national-geographicandtrade-sanctuary-reptile-terrarium-5210603.html

Does this mean my reptisun light needs to be 36 inches? Do they make it that size? I read on the forums the light doesn't go through the screen well, so how do I mount that light inside?
Also, I know it needs a heat lamp on one side, does the other side need light, or will the uvb light it up okay?
Will this be a good set up for an adult (it amounts to 50 gallons)
Im planning on using tile or paper towels as substrate (leos dont do well on sand either, so I'm used to the "less attractive" substrate)
I live in Florida, so i cant use Dubias as feeders. Also, I fed discoids to my leos and they freaked me out a bit anyway, so id really like to not go that route. What other insects could I use as a staple? I've seen supers and mealies are not good, although my leos loved superworms! I get how to supplement, Leos were the same with calcium/multivitamins.
Do you cook the veggies before serving? I know not the greens, but the squash?

What am I missing?

That’s a good tank. I have the Exoterra 36x18x18 with the front opening doors. I can’t tell you how many times a day I open the doors, feeding, cleaning and getting him out to run around. The Reptisun UVB does not have to be 36”, you can do just fine with the 24” hood, which takes the 22” bulb. The non adhesive shelf liner is very inexpensive & you can pick that up at Walmart, Bed Bath & Beyond or Target. It’s easy to wipe up messes & bugs won’t be able to hide under it. It’s also a good liner for putting tile on top, or just a few pieces of tile. Search this site for great information & there are a lot of members that can give you more advice. Make sure you get a digital probe thermometer or 2. That way you can get the temperatures right. It’s good to do all your homework before you start. Sounds like you’re almost ready.

Did you mount the uvb inside the tank? How do you do your uvb and heating?
I also heard vinyl tile is good, so i might consider that as well.
Definitely doing the probe thermometers, the stick on ones are useless.
Im trying to find out the difference between that cage and the exoterra one, but im not really seeing a difference.

I’m not sure what the difference in the tanks are, my Exoterra latch on the tank is not working so good. The spring inside the latch came off. I can still close it & latch it, but it does not really lock anymore. The lock on the National Geographic is different. I would say it’s more of a family lock, so kids might not be able to get the Beardie out. I did not mount the UVB inside, I would have had to cut some slits in the screen to hang it from zip ties. Mystic is really my nieces dragon, he’s 3 1/2 years old, but I’ve been taking care of him since he was a few months old.

I use the basking bulbs from Petsmart, I know I can get them cheaper online, but returns I don’t want to deal with. Some people are using the PAR 38 bulbs. I have looked at them, but don’t really know what wattage to use. Mystic is happiest when he’s running around the house.
This is his new sweet spot, in front of the fridge.