Most employers will have at least an overview of their benefits on the 'careers' section of their website (if they have one). Additionally, they'll almost always have a discussion of benefits (including healthcare) either with an actual HR person, or with the hiring manager. If they do, feel free to ask for more information about how the healthcare works if you don't understand the benefit.
This is likewise a great topic when they do the normal "do you have any questions for me?" bit at the end. "Hey, I'm new to the US and so I'm curious how your healthcare works in this company." is perfectly fine.
I would suggest that before you go in, you do some of your own research so that you understand the basics like HMO, PPO, etc. Generally, most plans will involve some portion of your paycheck (before taxes) going to healthcare, and some portion of said fee also paid by the company. Typically the things that vary are things like how much co-pay you owe on a visit (i.e. out of pocket; it's normally a flat fee like $20 or $30), if there is a deductible (and how much it is if so), caps on various services per year, and so on. So a little research in advance to be able to ask intelligent questions. Also, you normally can change your options each year, so decisions are not irrevocable.