@Shilpa Matlock actually the 1% rule is the gross monthly rents and it looks like you used gross annual rents minus vacancy? If the purchase price is $120k your monthly rent collected should be $1200 for the 1% guideline. No consideration for vacancy at this point. Once you start digging deeper I would then account for vacancy.
You also said you verified taxes. Did you verify what they CURRENTLY are, or what they WILL be after the sale? Most states I am familiar with trigger a tax reassessment when a sale happens. Estimate your taxes on the full purchase price to be conservative or go to your county website and they might have a tax estimator. Or take the millage rate and multiply by the purchase price. This is general advice. Each state and county is different.
And one way to estimate maintenance and capex is reviewing 2-3 years of the seller's schedule E's, T-12, etc. Even better way is to calculate an exact dollar amount that you should be saving each month, rather than using wildly inaccurate percentages. For example: If your average hot water tank lasts 10 years and yours is 5 years old then you should plan to replace it in 5 years. You determine that a hot water tank should cost you $1000 to replace in 5 years, therefore you should set aside $200/year for the next 5 years. Do that with every capex item and then figure out how much you need to set aside each month to be ready for those expenses as they reach the end of their service life.