Hi derryg, Welcome. The hike up Whitney on the main trail is difficult under any circumstances. 22 miles round trip is just under a marathon distance, but you have the added difficulty of 6000 foot elevation gain (appx). With that comes 6000 feet you need to go down. Going down is just as hard as going up in light of the fact your legs, lungs, etc are tired. I find that concentration is one of the most difficult things to maintain when heading down the trail.
There will be snow on the trail as seen in the numerous videos put up by Steve this last week. You would absolutely need crampons for snow. Microspikes just won't cut it at this point. The snow has melted and iced over, crusted along the trail, so it's a bit to late for snowshoes.
I will be going to Whitney on July 5th and I don't expect to summit as I'm uncomfortable in the snow and ice. I would think you could make a goal of Trail Camp as long as you have crampons. Going any farther might not be the best idea. The hike is gorgeous to TC and you will certainly learn a lot just going there. Great prep for another hike down the line. If you want to try it again, anytime during the week in September should be an okay time to get a walk in permit.