GET STARTED: Open the asset manager with the 'burger' menu top left.
or
NB: Are you in edit mode? Enter edit mode with the 
button top left or login
Asset manager toolbars
L-R: Albums, upload, search
L-R: delete selected, download selected, add/remove from albums, select all in view, unselect all in view
L-R: choose sort order, add existing assets to this album, upload new assets to this album, delete this album