Found a potential multi-family lead Not sure how to proceed.

I have a potential lead on a 24-unit apartment complex in my metro area. According to the tax assessor’s website, the current owners are out-of-state. So far, I’ve only dealt with smaller properties and local owners, so I’m not sure how to proceed. I’m not sure how to crunch the numbers on a multi-family of this size, and I’m not sure the best way of contacting the owners. Any advice is appreciated! If it turns out to be a workable deal, I would also be needing to take on a partner or partners.