Finding deals on Redfin or Zillow?

[Corey Samuelson]

So I'm using Redfin and Zillow to look at Duplexes in and around my hometown of Hesperia, California as I want to start out by house hacking. From a buying standpoint, how do I know if what I'm looking at is worth the list price? (I would of course make a lower offer)

I could go there and check it out, but I have no experience in being able to tell what a property is worth.

I'm considering calling the listing agent, but I feel like he/she would have more incentive to deceive me in some way.

Apologies for the noon question, I'm reading the BP book currently on rental properties. I just need to learn how to spot of a property is overpriced or if it's a good deal. I realize this probably comes through experience. I really want to take my first step though and I don't want to meet financial ruin on my first step.