Hi @alessandrotesta - Thanks for reaching out!
It's great to hear you enjoy hiking around the Sacramento area. Both the Sierras and the NorCal coast are such incredible areas. I'm sure you've had some really amazing days out!
While we are hopeful some other hikers from your area will see your post and connect here, we also wanted to share the Sacramento Area Hiking Groups on Meetup.com, where there seems to be an assortment of groups where you may be able to find someone looking to go on these ventures with.
Hopefully this helps!