Where to Find and Catch Chespin
From Pokemon Go Wiki
Chespin are found and captured in Nest and Habitat locations.
Nests
Chespin Nests are locations that consistently spawn Chespin.
Habitats
Chespin Habitats are spawn locations where Chespin is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: