If you can get financial support to get a duplex/triplex, I would recommend this.

@Serge Hounkponou Recommend you first figure out the property Class you want to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

I'm a little biased (am the owner) but seriously pumped to see you recommending it.

I see you're in the Boston area, so if you're looking for cash flowing markets I'd recommend Lowell, Fitchburg, Leominster, just to name a few.

For flipping I would also normally not recommend adding an ADU.

Florida is a unique state for MHP law and the insurance has gotten very expensive there too.I recommend checking out @Frank Rolfe's mobile home university content if you haven't already.

Greg, Would you recommend syndication investments to someone who comes here to learn real estate investing?

Starting with local credit unions is a good idea.2 - I recommend starting your search with a Realtor who specializes in working with investors.

Which sites do you recommend for pricing? 

When a real estate licensee does it, they look at the data, and recommend a price based on that data.