first mower purchase

so im torn about my first mower purchase,
this is the predicament im having, i currently rent one side of a duplex with a fairly nice yard, this year i decided to give my landlord a break and do the mowing and snow removal for him since him and his wife had a baby a few months ago. the reason for the mower purchase isnt really for this place, i plan on buying a house next year and i would like to have all of the lawn equipment purchases out of the way before the move i dont want to have to drop a bunch of money to do the lawn right after buying a house.
the question, what type of mower do i buy? the place im at doesnt have a huge yard but its open so i could use either a push mower or a tractor but i have no clue what type of yard i will have when i move, if i buy a push mower and end up with a big yard it will mean another purchase, if i buy a tractor and end up with a tiny or tight yard it will be overkill.
my other thought is to try a husqvarna articulating rider to deal with a tighter lawn if needed but will still work fine for what i have now, but thats the most expensive option.

any help would be greatly appreciated as i will end up making this purchase before the spring hits