I'm still used to seeing "Drive C" and stuff like that. I suspect that I am my own worst enemy. I keep folders of my work on my Desktop, and probably all my years of work are stuffed in there in /sda1 (I have no clue what that means in layman terms, other than it is a partition).
Think about /dev/sda1 being equivalent to "drive C" and /dev/sda6 being equivalent to "drive D", probably you have copied your own files to "drive C = /dev/sda1",
if you move your files to a desktop folder, supposing you are not working as root, your files will go to /home/<login id name>, therefore on /dev/sda6.
Of course, as suggested from uncleV, you will have better time resizing the partitions, but it can safely be a second step, if I understand correctly your words
you don't have much practice about partitioning disks.