As @galgalesh said, you can ignore the cgroups warning. Support for cgroups v2 is in development, but has not been rolled out.
The cause of the sudo error is that /snap/bin is not in sudo’s secure_path configuration variable on Fedora, so it does not find your auto-cpufreq executable. You should be able to run sudo /snap/bin/auto-cpufreq or sudo snap run auto-cpufreq instead.
Alternatively you could try adding /snap/bin to the path by running sudo visudo and change the path.