as everything in linux mountpoint is a file ( be precise), actually it is a directory where specific files and directories will be stored, you'll need at least three mount points:
/ - root mount point
swap - a swap file for memory management
/home - this is where users files and dirs are stored
then there are others like /usr - for programs installed
/var -where the variable files and dirs are
/tmp - temp directory and so on, the advantages to have mount points are first you can unmount a filesystem if not used, second if your system is going down (crash) you can save the files that are in /home and others, and reformat only a troublesome mount point.
Read the documentation with the distro it explains everything in an elegant way.