I have no idea where to start.

They tend to start doing "fire sales" which means dropping prices which causes all of the homes they closed on the previous 12 months or more to lose value based on new discounted comparable sales.That is why you see builder always offering crazy "Builder credits" which in most cases are "ghost" funds. 

What do you suggest I do if I want to start investing in multi family?

I started with flipping properties, then started doing direct-to-seller marketing, and transitioned our operation to wholesaling only.

Start by reading the Ultimate Real Estate Investing Guide: https://www.biggerpockets.com/guides/ultimate-real-estate-investing-guide/introduction2.

They have been very difficult tenants from the start, and I do not trust them unfortunately. 

Really just looking for like minded people who aren't into gate keeping and don't mind lending a helping hand to a total beginner!

And while you are out doing door hanger, you can scout out vacant properties, and start your investing career with a wholesale.If you want to be an investor, I would get my real estate license.Hope this helps.

(PA, DE, NJ) But this is totally dependent on your location. 4) What type of loan product are you using?

I know many people who started flipping in this manner, in fact, it was my idea to get myself started this way.