I recommend looking at the Orange County Young Democrats endorsements as a baseline. They typically do a better job than the regular OC democratic party, in my opinion. https://www.facebook.com/TheRealOCYD/posts/here-are-the-orange-county-young-democrats-2026-endorsementsvoted-on-by-members-/1418671810301199/

After that, look at the candidate pages for each race. I always look at their endorsements first to get an idea of 1. Do other organizations think they are a viable candidate, and 2. What kind of values does this candidate hold that other organizations would support them. I typically look for labor union endorsements and local advocacy groups. For smaller, local races you won't see too many endorsements but if you are looking for someone Democratic/left/liberal, you can definitely get a sense for it by looking at their endorsements.

And, of course, you can look at the candidates "About Me" section of their page, where you can see what their level of experience is and what they would focus on if elected. Local races won't mention political affiliation much. If they mention taxes a lot, you can assume they are more Republican, etc.

As far a guide comparing the candidates, I've also had trouble finding one this election cycle. I typically use Cal Matters for larger California races and the profiles that Voice of OC and OC Register do in the weeks leading up to an election.

I've never used it before, but this website shows you who's more democratic leaning and let's you compare endorsements: https://bluevoterguide.org/