i have some trades i've worked with a few times and if i ask them for a rough estimate they'll provide it. 

If possible, include in your welcome kit the location of a drop off laundromat (they wash, dry and fold for a fee).Make life easy for your residents, and you will be rewarded. :)

I'd imagine there isn't enough time to get a conventional loan approved for the property before the auction date?

I would spend time looking at comps on Furnished Finder and Airbnb, see which properties are current vacant vs properties that have availability in the future.

When is the best time to start incorporating these professionals during the journey? 

Ok I will check those websites out, Thank you.There's a variety of ways to get a deal in front of you (I'm mostly a flipper), but basically if it looks promising, I run custom comps queries and check the current & past $/sf of renovated/distressed product in that city or zipcode.Here's a chart on 90066 I generated from my tool under Market Stats > Sales Data > Specific Zip Code:- My above chart (more available) shows the Avg Renovated $/sf (High) over time in this Zip Code, something completely different than charts/providers based on Averages/Medians only, like every other platform (RedFin Below, https://www.redfin.com/news/data-center/):- Can't select smaller locations such as City or Zipcode for their $/sf data, so it's useless helping me underwrite/verify a deal.- Can set Zip Code for Median Sale Price data, but again it's the median/avg so it's useless helping me underwrite/verify a deal.Then if that looks decent, I'll run Sales Comps, and get a quick summary of some key metrics based on those comps.

MF is still, and will always be very attractive, but most trade off-market and requires a huge time investment to build relationships with current owners.

I am a first time rental property buyer and I have found a 16 unit multifamily building and I am wondering if this is too much to handle for a first time buyer/landlord.

As time moves on and people are stepping up their design game (As an STR Designer this makes me SOOOO darn happy!)

When it comes time to actually invest, you will typically be required to show some sort of verification - either a signed financial statement if you meet the requirement on net worth, or income tax returns if you meet the requirement on income.