how would i go about doing this?

MCreator Noob Here!

Basically, I'm trying to make 2 blocks/machines that work together. One machine stores items, and the other machine takes out the items and converts them into other items if they are part of a certain tag. So, for instance, if the storage machine has a fern, the conversion machine will take out the fern, because it is part of the tag, and will convert it into coal. How would this work? I also want it to function even if the GUI is closed.