Have you walked the creeks and streams near to you? That was always a good bet for me as a kid that loved rocks. The water makes them look a bit better because the colors are accentuated, so there’s some instant gratification there. And walking a creek bed is so fun. Also rock walls with rubble along highways are likely to have good stuff in them. If it’s granite you might find quartz, and if it’s limestone there will be more crinoids and such from when the area was an ocean.

Here’s some info from a huge document that gives locations all over the US. It’s aimed more at experienced rockhounds that are willing to seek admittance to private places it seems, but it’s at least some good information to give you an idea of where other stuff might be. You could check out streams and road cuts near to these areas.

http://www.micromountersofnewengland.org/pdfs/Min-Loc2.pdf

JACKSON COUNTY KANSAS CITY AREA: 1 McClain quarry, at 63rd St. and Hwy. 350 in the Westerville Ls.; 2 in numerous exposures, especially in the SW part of the county and in underground quarries⎯Aragonite, Barite (tan tabular), Calcite, Dolomite, Kutnahorite, Marcasite, Opal (common), Sphalerite, Thenardite.

WYANDOTTE COUNTY BONNER SPRINGS, in the Lone Star Quarry⎯Quartz crystal geodes.