Hi All, I need to replace a rim that is cracked around the spokes. This is my bike: https://www.bikes.com/en/bikes/whistler/2015 (Whistler 70)

I can't find any info on my current clincher rim (700C) for my 32mm tires. I'm looking to replace it with a rim that is "fast" on pavement and can handle well on dirt and gravel trails. I don't know much about rim profiles or rim technology, etc, so I'm looking for some suggestions on manufacturers of rims that perform well and aren't too costly. Also, any links to info on how to choose a rim would be helpful too! Thanks

Tubed or tubeless? then budget. what you asking for "fast" and aren't too costly very rarely exist together

Can you do the work yourself? unless you can find a rim with an identical ERD (the diameter) you may find it cheaper to just replace the whole wheel/wheel set, as you will need to replace the spokes/nipples in addition to the rim.

Would be looking for/at brands like Shimano, Mavic, or see what your LBS has.

I'll likely be doing the work myself with the help of YouTube videos. I was hoping to get just the rim to save on the expense of an entire new wheel set.

Pick a rim width that is appropriate for the tire you are going to use.
Aero rims tend to be heavy, which is pretty much a negative for other than high speed use.
Handling is more tire and operator perception.

The approach I would take with an unknown rim to replace-
Measure a spoke. Both sides if a rear or disc hub.
Use a spoke calculator and determine an ERD for that spoke length and number of crosses. Just plug in different ERD's until you get the length correct.
Find a rim with that ERD.
The reason I'd work this way is your spokes might not be the "best" length as installed in the current rim. You may as well make them a "best fit" for the new rim.

Don't mess with old nipples. Wire brush the spoke threads.
That still won't give the "feel" of new spokes & nipples, but failure to do so makes the job much tougher. Nearly impossible if you are inexperienced.

I would suggest an 18 mm inside width rim. My favorite in that size is the Velocity Dyad because Velocity rims are round and flat, so they are easy and fast to build; just tighten each nipple the same amount you are really close. The Alex DM18 is pretty good, and less expensive. The Sun CR18 is even less expensive, and takes a bit longer to build, and it is not possible to get even tension and a true rim.

I recommend following: https://www.sheldonbrown.com/wheelbuild.html for building wheels.

Do the math on this, as spokes/nipples and rims aren't cheap, you may find it's cheaper to just buy a complete wheel, go back before factory wheels existed (late 90's early '00s), and building made sense, if you are starting now, would really question why unless you needed something non-standard.

Given what the op said, a wheelbuild without a tensionmeter or any of the tools will NOT be cheaper than buying a wheel outright. Not even close.