Don't forget that your new DSLRs defaults to the optical viewfinder for shooting stills. To use the "live view" display you must press the "movie" button just to the right of the viewfinder, that is, above the top right-hand corner of the display. There's a red dot beside it. You'll hear the click of the mirror, and: presto. Otherwise the display will come alive only for reviewing what you've shot, and for Menu, Info and Q data.
If you're coming to this from a pocket cam, try using the optical viewfinder. The autofocus will seem like lightning.