If the plant has been submersed in water it's whole life (which is probable) then yeah, it's going to shrivel up and die when it's not submersed. Some plants can handle not being fully submerged in water but you should just get it into the tank as soon as possible. You can pull off the dying leaves; only the ones with brown at the edges. The other ones that looked crumpled should do fine in the water. They need water to keep hydrated, unless you spray it with water every 4-6 hours or so, it's going to dry out.
It won't hurt your fish or nothing unless the entire leaf dies and you leave it there. If you take it out right away it will be totally fine. In fact I really do want you to put that into the tank now so that it can stay hydrated.
And for co2 yeah, it did slip my mind, sorry! It's not essential for planted tanks or NPT's. It can help for sure but if you don't have air stones and bubbles stones everywhere then it will be fine. What happens is when you aerate the water, both oxygen and co2 exit the water column, so if you have no aeration in the water (you can have movement but not aeration) then you keep the co2 in the water.
So because co2 can exit the water so easily, people use the co2 systems to put it back into the water, but no it's not essential. But you can rig up your own DIY co2 yourself and you will have no worries of overdosing the tank. Yep, it's possible to over populate your tank with co2 which can lead to fish deaths so that's why you need a regulator/bubble counter with the fancy systems. With DIY, it doesn't make enough pressure to make enough co2 to hurt anything so there are no worries there.
But if you dose with liquid fert and the root tabs, there's really no need for co2 unless you want to dabble in it yourself. In that case you can use all three but I would use half the dosage for liquid fertilizers and half of the root tabs so that you're not overloading your tank with stuff. Make sense?