Things to do in Skardu
Dunes at dusk, the Kachura lakes, the fort up at Shigar, the Deosai crossing, and the treks you cannot improvise.
Sooner or later someone in the bazaar will offer to take you to K2. Skardu divides very cleanly, and you want to know which side of the line you're on before you get into anybody's vehicle: there are days out from town, and there are expeditions. Almost nothing sits in between.
Day trips from town
The Katpana cold desert. Dunes at over two thousand metres, right on the edge of town, which is the sort of thing that sounds made up until you're standing on one. Go for the last hour of light. The sand turns and the cold arrives fast, so bring a layer you wouldn't think you needed.
Upper and Lower Kachura lakes. Twenty minutes out. Upper Kachura is quieter and it's the better of the two by some distance; the lower lake collects the day-trippers and the boat touts. Go early and you'll have it to yourself.
Shigar valley. An hour or so north, where the road turns properly serious and keeps going towards the Baltoro. The restored fort-palace is the reason to stop and it earns the stop. Easy half-day, or a place to sleep in its own right: see where to stay.
Khaplu. Further east, and always a longer day than anyone tells you it will be. You need a vehicle and an early start. With both, go.
Deosai
The second-highest plateau in the world, and the surprise is how flat it feels once you're on it. The peaks stand off at the edges and you spend the day crossing something closer to a green ocean, with marmots in it. The track between Skardu and Astore is unsealed. It's open for a short window and buried under deep snow for the rest of the year, and no authority publishes a reliable opening date, which is why passes and roads tells you to ask in town instead of trusting a page.
You can force it into a very long day. Do it over two if your schedule allows.
The treks, and being honest about them
Concordia, K2 base camp and Gondogoro La all start from here, and not one of them is a thing you improvise. An operator, porters, permits, and time measured in weeks rather than days. People do turn up in Skardu hoping to attach themselves to a departing group. It very rarely works.
If that's why you're coming, start with tours and treks for what an operator actually does for the money, then foreign versus domestic tour pricing for why the figure you're quoted may not be the figure the person beside you got.