Many volunteer SAR orgs will run an academy or training program, so don't worry too much about quals/certs going in as you can get those afterwards.
Make sure your criminal history is clear, as you will get background checked and fingerprinted through the Sheriff's office (they are mandated to oversee SAR ops.)
It is worth it, though sometimes challenging if you have an inflexible job or family, but even then there are workarounds and options.
Cheers,
-mox