Deal Analysis help in Houston

[Mike Peel]

Morning everyone! I am looking into a turnkey 3/2 SF Home (1440sqft) with a detached studio garage apartment(400sq ft) in Houston. Below is what I compiled. Is there anything I am missing? Anyone have comments on the deal? Anything I calculated wrong? This will be my first real estate investment. House Purchase Price 121,351 20% down for loan 24270.20 Mortgage Balance 97080.8 Mortgage % 4.5% Term (years) 30 Mortgage Payment $491.89 Tax Payment $ 272.73 Home Insurance. $83.33 Total Fixed Cost $ 847.96 Estimated Repairs 120 Total Fixed/Variable Cost $ 967.99 Potential Rent 1800 (1200 sfh, 600 studio) Vacancy Rate (10%) 120 Net Income $1,680.00 NOI $14,447.19 Cash Flow $8,544.46 Cap Rate 11.91%