I started trapping rats (muskrats) when I was 10 years old (1973). Caught thousands of them. A few mink, skunks, weasels, ducks, pheasants etc... Back in the day, I was getting $7.00 for an avg rat, and upwards of $13.00-$14.00 for a nice big one. Bringing home a check of $750-$1000 a month as a 15 year old kid.
I trapped beaver too. But by far the most difficult was Mr. Wiley Coyote.
Read lots of books, talk to lots of old timers and then develop a routine that works for you.
Good Luck !