Hey :)
Elementals are what we call an effect; they're a variation of the lineart that comes in all the colours of the creatu. You can check out colours and effects under the Information tab in the Creatu Species and Creatu Colors pages!
Elemental is the effect that your pet receives when it gets blessed by the shrine. So with the shrines you hand in pets, items and eggs for reputation and you will occasionally receive blessings where you can choose one of your pets from that planet to receive the elemental effect (but check first if it can get the effect, because not all species have it yet)
Candles are used to temporarily change your planet of residence for 24 hours. There are also residence permits sold in the cash shop, which give you permanent planet changes.
Hope that helps, let me know if you have any more questions :D