The trail is a very obvious trail for almost its entire length. There are some places where it crosses a rocky area or two or makes a switchback where you might stop to ponder the route for a few seconds or so. But in the main, the stone steps, cleared areas, or rock borders mark the way quite well. That would be the case until you reach the snowy areas where the trail might be hidden at this time of year.
The one area which can cause confusion (and has) is at Trail Crest (not Trail Camp). From there the trail drops a couple of hundred feet on the west side of the crest. It reaches a junction down those couple of hundred feet. The way to Whitney is UP to the RIGHT. The John Muir Trail goes down. The confusion on the hike back after Whitney. It sometimes occurs because on the way down, when tired, folks sometimes miss the trail signs/junction and forget they have to head UPHILL again for a few hundred feet back UP to Trail Crest and then downhill to Trail Camp.
Have a good hike