my first buy and hold deal, need answers to some questions

[Mario T.]

hello bp community,

im interested in my first buy and hold property that a wholesaler brought me.  but i'm hesitating because im not sure if it's a good deal and what question i should ask.

it's townhouse 3b/1.5b 1006sqft was recently renovated within the last 3 months.  there is a tenant in place that is current on rent $800.  they are asking for $55k.

im interested in conventional loan which requires at least 20% down on rental property (=$11k) and i calculated vacancy rate of 10% (=$960 based off of $9,600 gross rent), as far as i know there is no repair needed, but i'll factor in 15% (=$1440), what type of monthly expenses should i factor in? and when should i request the lease agreement to read it over myself? any other question i'm missing?

thanks for the help