If you don't see it as a plain mass storage device, it is possibly using the MTP or PTP protocols. These are often supported at the application level by image/photo managers such as Gwenview, Digikam and perhaps GPhoto. Some cameras can also switch between mass storage and PTP (on my Lumix, this was done with Print mode).
The other solution is to take out the storage card and put it in a card reader(*). This makes it behave as a mass storage and all your file managers will be able to read it (on my Ubuntu this appears in /media/{my_id}/{some_label}). This is also usually a lot faster (the USB link is slow).
(*) External but also built-in in many laptops these days.