I'd recommend shooting a couple matches before doing any goal setting. They have a bit of a different flavor than the shooting sports you mentioned trying.
But to answer your question, the best benchmarks for the respective USPSA classes are the classifiers themselves. Mind you, those scores aren't going to correlate directly to actual match performance necessarily, but that's another topic all together.
The classifiers vary a bunch in difficulty, often with no apparent rhyme or reason. But collectively, they're the barometer by which you're going to be measured within the classification system.
Print a few out, go set em up and see where your scores shake out. With the understanding that you'll be shooting them under pressure, in the middle of a match, one time for all the marbles, etc... when you're actually getting classified.
Here's a list of them:
https://www.uspsa.org/uspsa-classifier-list.php
Here's an online classifier calculator that's a good handy resource. If you plug in your hit factor (points accrued/time), it'll plot your percentage and class for you based on current classifier data.
https://azshooters.org