@Jordan Vance In my market beachside cashflow and appreciation do not go hand in hand. For example a $300k single family home will rent for about $2k per month and cashflow little to none by time you figure in, taxes, high insurance rates, capex... You can purchase a palm bay house for less than $100k that will rent for $1100-$1200 per month. Good cashflow but not likely to appreciate as rapidly as a more desirable beachside neighborhood. Also, I don't see multifamily appreciate as rapidly either. Most investors will value a multifamily property based on cashflow, not comparable sales. Also, we have a very low inventory of multi family units that come up for sale. Many of those are priced with little no no cashflow..
As far as finding your niche, normally it starts with the opportunities available to you. If you have access to funding or your own cash, you can start acquiring rentals. If you need to build up cash, maybe you wholesale or flip a few properties. The best advice I can give you to get started is to select a small geographic area that you like and become an expert in that market. Drive the neighborhoods, look at the sold listings, see the rental rates and demand.