Investing into gas station or laundromat

[Duc Ta]

Hi,

I'm not new to investing. However, i'm still a newbie to investing into business like gas stations or laundromat. Beside the balance sheet, profit and other things, my stupid question just come across my mind as i did buy home and used to rent apartment too. From buying home and renting apartment, if the property has HOA or renting, the wear and tears outside such as roof, walls will be repaired under HOA. These are major costs. Now come to laundromat or gas station, what are those repairs belong to? Out of owner pockets or someone will do that? I saw some gas station has large number of gallons sale bt low commission which i think commission is the main way for gas sale (we know they have food sales, other things sale which are considered as inside sales and deli sales). I tried to used 20% rule for setting of the expenses for repairs, it still not much profitable not counting for the labor and other expense. Anyone can help?

Also anyone can give me tips for starting