So I make this decision carefully, and most of the time I probe deeply once under contract. 

WSJ Prime is 8.5% and most primary residence/FTHB mortgages are high 6's to low 7's.

As mentioned above house hacking is a great way to get started since its low money down as your primary residence, but if you already own your own home you may look into tapping into your equity and using a HELOC to help with downpayment.

Investment Info:Single-family residence buy & hold investment.

Would be ideal to try and qualify for §121 exclusion - which allows you to exclude up to $250k of gain for selling your principal residence ($500k for MFJ).

You will be taxed differently on the capital gains if it is your primary residence (ie you lived there recently) vs a rental. 

I am about to turn 21 years old and reside in Maryland.

@William CoetI would be very careful providing sellers tax advice as you don’t know their situation.

Plus I wasn't married with kids, so I was comfortable taking the risk.I found that owning my primary residence as my first "deal" was a really great way to get into real estate.

Solution: Carefully jack up the floor in that location and add a steel post there for support.