Home heating oil?
 

It’s my first time using this…I live alone and am not a person who needs the thermostat to be on 80 all winter lol…

Landlord says the tank holds 250 gallons. How long would that last? Any advice/suggestion?

I can't answer because we have natural gas but I would think there are some additional parameters- how many square feet are you heating? Apartment or house? Average temp in that region?

Give or take a month depending on the size of your home. If it's an apartment you could get close to a month and a half depending on how cold your area is.