Even if investors test use you on a trial basis to just fill their rentals at first, it may be worth it, no?

Your're trying to target the investor who's had 1 rental for 15 years and wants to get rid of it.It's different for every area so this might be a trial and error for your specific farm area.

I have taken trial memberships to websites that offer video training on how to get started. 

If you're up for the trial-and-error approach (and consider that part and parcel to being an entrepreneur), no slings from me.  

And how much trial and error and mess up money will it really cost me in long run.

Wise on this one I think many of these folks if they would just take the time and energy to get a RE license and learn from that angle and get paid to learn they would do much better than thinking they can just learn from a guru or even on BP  its nice to talk about it all and there are many very experienced and successful folks However I suspect most of them learned the old fashion way trial and error not just reading on line how to get rich in real estate ..

I learned through trial and error, but again this kind of work always came natural to me.

I didn't just happen into yellow letters, it was a trial and error process that included a few websites (back in 2009-11 when squeeze pages actually did work).

I used to manage a gym and during the first 30 days of membership (free trial) people came maybe once a week.

My wife isn't totally on board, so its a trial run for us.