I agree with hunter GT: I used to get lots of permissions from cold-call knocking on front doors when I was a kid (in the late 1970s with my Whites 66TR, and my garrett Groundhog). But as I got older, I got less permissions and more rejections. So you're actually better off as a youngster, than a suspicious adult
I disagree with kiddo1979: Don't bargain for yard work. Because 1/2 or 3/4 of them could be silly low results (clad only, or nothing, etc....) And before long, you'd find yourself doing yard work for nothing. Also, the mere act of "offering yard work in exchange for blah blah", puts you in the immediate camp of a sales-person. And we ALL know what we do with door-to-door salespersons, right? We say no thank you and close the door.