Alright here's what you need to do and I guarantee you will have the biggest and coolest VFT on the block. It will look so cool your chickens will be scared of it.
Environment
This is the most crucial part of growing flytraps, and will have the most effect on how healthy and big your plant gets. This is much, much more important than feeding.
Remove that plastic "terrarium cube", throw it away, put a curse on it so it can't come back. That is only for protection while shipping, and if you grow the flytrap with it on, it will suffocate and die guaranteed.
Set the now-uncovered pot in a
small bowl or tray with a little distilled water, and put it outside, preferably up high on something so the chickens can't get into it. Ask your grandma, she might be able to help you find a place. Don't worry about "partial shade" or whatever, find somewhere that gets the full sun beating down on it. A flytrap will do ten times better outside than inside. Flytraps need lots of hot, natural sun. Keeping one inside will lead to pale color and long sickly growth.
The first few days it's outside, the existing leaves might get red looking. This is basically "sunburn" because your flytrap is a wuss and is used to being inside in low-light conditions. The new leaves and traps it will put out will be tough and won't get sunburn. In the outside sun the inside of the traps will color up and it will look great.
If you absolutely must grow it inside, I suggest buying a small bendy-neck desk lamp and the highest watt Compact Fluorescent spiral bulb you can find, and putting the bulb extremely close to the plant. Like literally 3-4 inches away from the plant. Don't use regular incandescent bulbs because they produce too much heat for very little light, and will dry out your flytrap.
Feeding
Don't worry too much about "feeding" the plant. A flytrap can grow big and healthy without ever eating a bug, and if it grows outside it will catch enough bugs on its own. Feeding is mostly "just for fun". Live bugs work best but can walk out of the traps, triggering them without being caught which is a bummer. Feeding them dead bugs can be done and is a great way to feed, just make sure they're freshly killed and not dried out shells that have been sitting on a basement windowsill. The way a trap works, you will have to do a little work to get them to properly digest dead bugs for reasons I will explain.
Traps trigger when something touches two of the six trigger hairs, or one trigger hair twice. Touch a hair once, and the trap is primed and at attention. Touch it again and BANG it snaps shut. But this isn't the end of the process.
Trap closing and digestion takes a lot of energy out of the leaf. Each trap can only close and digest 2 or 3 times before it is "
worn out" and will no longer work. (don't worry, your plant will be replacing old traps with new ones constantly) The plant doesn't want to waste precious energy on twigs or little pieces of leaves that might fall in the trap in nature, so it has a clever way of detecting whether the object it caught is alive or not before sealing itself airtight and starting digestion.
You'll notice that when a trap first closes, it's
loosely closed and you can see inside through the eyelash parts. If there's a bug in there you can look closely in and see it running around in there. Now, when the bug keeps freaking out and moving around, it keeps touching the trigger hairs from the inside. This is how the trap knows it has a live meal. After touching the hairs some more from the inside, the trap will
seal itself
airtight around the edges and fill with digestive juices and melt and drink the bug.
If you put a dead bug or twig or pebble inside the trap and it closes, if the hairs don't get further stimulated, the trap will open back up and "let it go" without beginning the digestion stage. If you want it to eat freshly killed bugs you will have to stick them in the trap, touch the hairs and close it, and then after it's closed get a tiny pin and
carefully reach in through the gaps in the eyelashes and flick some trigger hairs a few more times. An hour later when the trap is sealed you will know it worked. (This may also be done without the pin by very gently squeezing the sides of the closed trap with your fingers but this might weaken the trap and it's been a while since I've grown flytraps so I might be wrong. you'll have to test it out yourself)
When the trap opens back up, only a hollow exoskeleton may be left, which will either fall out from the wind or get washed away from a raindrop. (although if it stays there and goes though another feeding cycle, it's no problem. trying to remove exoskeletons may accidentally trigger the trap closed again)
When feeding try to keep bugs no larger than 2/3 the size of the trap. Feeding it something that's too big will be too much for it, and the trap will rot and die. If a bug only gets
trapped partially or has a leg sticking out the side, the trap may rot from that end and die. I don't know where you live but if I fed my traps the big black ants I have crawling around my house the traps would get a black spot where the ant's head was and rot, so some bugs might have acids or enzymes the traps can't handle. Don't worry though, because new healthy traps are constantly being produced.
Go nuts.