Only your GM can can organize handouts and character sheets into/out of folders. If you are the GM, left-click and hold on the sheet or handout icon and drag it to where it needs to be. To drag it into a folder, hold it just below and to the right of the folder name. It takes a bit of practice. Remember that to move a handout or character sheet within the journal, click-&-hold on the icon; to drag it onto the map, click-&-hold the name.