What are the best ways to start gravel biking for a complete novice (in the Bay Area)? I recently got a Cannondale Slate and because I’m a complete novice, I’m a little hesitant in starting to ride on trails alone. I’m mostly wondering if I’d have to perform many jumps (which I don’t know how to perform) on the trail. Any advice on trails or best practices would be highly appreciated.
Welcome to the Bay Area! First, you should become a member of Bike East Bay - they provide advocacy as well as produce bike trail maps for the east bay. Being a member gets you a discount at most east bay bike stores. 

Second, the gravel trails around here are all fairly gentle in terms of terrain except for some steep hills. You could do them all with a hybrid if you're fit enough. So my advice would be to just find some trails - either along the coastline where it's flat - or in the hills where you get the view -- and just do it. 

The best way to learn is to just ride! If things get sketchy just take it slow. There are group rides scheduled through Bike East Bay, REI, and other organizations. Check through them or places like Meetup. 

PS: You can find some very difficult, double black diamond trails for mountain biking in the east bay but you'd really have to go out of your way to look for them. Marked trails on the bike trail maps (and on google maps) are all beginner level.