How do I choose a replacement wheel rim?
First, you have to decide whether you want to replace the rim (the ring shaped outer part) or entire wheel. If the wheel is otherwise in good shape, swapping the rim is an easy task and a shop should charge less than for a full rebuild.

For wheel you have to match size, axle thickness, spacing and cassette and brake disk interface. Fortunately, for quick releases there is only one common axle and spacing standard. If you want to keep the discs, you will need hub with Centerlock rotor interface. For cassette interface, the common exceptions are 11-speed road, Campagnolo and Sram XD, and your bike doesn't have any of these. In practice this means you'll want a Shimano hub.

If you swap the rim, you'll need to match size, spoke count and ERD, the diameter at spoke holes. Rim width does not need to be exact match, but if you are using the same tires it shouldn't be changed much. A rim with different ERD requires new spokes and relacing the wheel from scratch.