Yes - year round
Yes, we sail year round. We have one race per month, and in some months more. There is no race in December.
I sail virtually every weekend and most spring-summer-fall days after work and will take crew out to practice any time they want.
San Diego has a big racing scene and you could be racing every weekend and some weekends Saturday and Sunday on other boats. Learn what you are doing and you can get out just as much as you desire.
As to where to live and work, I can't help much. Work depends on your skills. This is a military town and there are lots of Navy and Marine jobs. It is also a tourist town and there are lots of hospitality jobs. If you want to work on a boat (and work hard) you maybe could get a job on one of the day or half-day fishing boats.
Cost of living is high here. There are lots of apartments available. Cost about $1000/month at the low end. You are single and 30ish. I'd look in Pacific Beach, or Ocean Beach.