Yes. Once on land, you walk to the Geiranger camping, over a small bridge, then turn left. You will see and hear the waterfall. You climb along the waterfall by stairs and the Fjord museum is at to top of the stairs.

You can get there two different ways. From the point where you get off your boat onto the docks you can take a steep switchback road up the hill right behind the shops at the dock. Or, you can walk around the front of the town along the water until you come to a campground and take the road up along the river to a staircase that climbs next to the falls. You can make a round trip from either road. Both walks are so beautiful

Time depends on your fitness, which direction (up or down), how often you pause to take photos of either the view over the fjord or the waterfall, whether you are battling the cruise ship hoards doing the same walk, and whether you visit the Fjordcentre at the top. If you are fit and do it in a hurry before the cruise ship hoards clog up the walkway, 1hr return walk without visiting centre. Worst case (unfit, take lots of photos, battling the cruise ship hoards), 2hrs return. Add another hour to see the Fjord centre (see our review).

In general I found the port areas in Norway to be quite safe, and I'd have no hesitation about walking around on my own. For this particular attraction you'll probably find there are lots of other people who are also walking there.