Define "upstate"? Are we talking Bear Mountain State Park (which is only about an hour north of NYC)? Or are we talking Mid-Hudson, like Catskills? Or actually upstate as in Adirondacks? Letchworth or Allegany state parks?
If you're going with Jeep trail ratings (though there are ratings for Jeep Jamboree USA and Jeep The USA that are different scales) for stock Crosstrek, I'd likely stick to the lowest of them. Stick with 1-2 rated trails. American Trails has information about other rating systems, too, like a color-coded shape system (like some skiing trails).
Stock Crosstreks are surprisingly capable - enough to get yourself into some trouble. Remember that you don't have stock skid plates, just thin plastic, so hitting a rock could have real consequences. Also, your approach angle isn't great, so it's easy to cause some (hopefully only cosmetic) damage in the front.
Check out local off road supply store if you have one. My local "Jeep" store has an experienced person who owns a Crosstrek who's been very helpful. His Crosstrek is highly modified but he does know the local sites and seems convinced of the California markings for trail difficulties are pretty accurate for Crosstreks with trails beyond Easy requiring very careful driving to avoid damage. I found in my unmodified 2018 Crosstrek that anything beyond Easy had moments where it might be easy to remove your bumper or be holed by a sharp rock. My street tires, even when aired down, were pretty desperate for traction in the (then) highly dusty and larger slab rocks. It was still lots of fun. Safe travels!