1) In a forum your heading is important to attract the correct people. Do not use titles like "Please Help". Most people here need help. It wastes peoples time if they have to read messages they cannot answer. Use something like "Need correct driver for Canon MG8150"
2) If you have downloaded the ordinary version of Linux Mint you need the driver for Ubuntu.
Linux Mint is based on Ubuntu, which in turn is based on Debian.
3)Linux Mint and Ubuntu both use Gnome, which is called a Desktop Environment (DE)
KDE is a different Desktop Environment. It is possible to download a KDE version of Linux Mint, but I would think that you have not done that. The KDE version of Ubuntu is called Kubuntu.
4) RPM stands for "Redhat Package Management". If you are using Linux Mint it is not for you. You should go for a .deb for Debian.