such much is wrong with that statement
transactions are information about where funds came from and where their going to.
a confirmed transaction is when said transaction has been included in a block, and said block has gone through the mining process and majority accepted by nodes verifying theres nothing wrong with all the data.
mining is the process of using math to produce a very hard to replicate hash of the blocks initial id. making a super strong ID that takes effort/cost to undo/replicate
mining is NOT limited, because even after the 21m coins get into circulation, miners can still mine and just take a fee from existing coins rather than creating more coins, by charging a cost to those making transactions.
if there was no more mining. then transactions dont get confirmed. thus making bitcoin useless. so mining has to continue to have the ability to make transactions.