I am thinking of either going through an online funding platform or advertising the opportunity or using crowdfunding.Which would you advise me to start with.Note that I am excluding taking a loan here because I am only 18 and in university, all banks said they wouldn't lend to me.Thanks!

In a way, I'm attracted to the inner city as it is a really good cross cultural experience. 

Large, pro cabin companies that will take 40% of your gross income (they'll do an intro rate of 20% to rope you in), that do not use many of the major booking platforms.2.

Another option to get into your next property might be to put it under contract and then go to a Lender and offer to cross collateralize both your properties for one loan. 

That would be an easier pitch then trying to get a seller to trade equity they need for their next home for a note.I get letters from local companies constantly for my notes so I am assuming they look at the county records to cross reference material to send me ads.

Market of scale is not 3, 4, 7 odd unit's but when one crosses the threshold of a portfolio being self-sustaining, which often is around the ~25 unit range if SFR.

I like the BP rent estimator as a starting point, but i always verify by doing my own research, no matter the platform.

You would think that might attract some sketchy people on such a platform, don't know if I could bear doing that.

I guess you can learn by losing money but that is counter to my approach to business.I was taught to always have "two or three witnesses" ( sources ) before I put any credence into an answer so I cross reference with other sources.

On our platform, we have few buyers that are paying close to par on assets that meet their buying criteria.