Accommodations vary college by college. Students attending Mansfield College and St Edmund Hall should expect to live off-campus, within walking distance of the University. If you attend Oriel College or Lady Margaret Hall, college residences are an option. Explore your options using these virtual tours:
Mansfield: https://www.mansfield.ox.ac.uk/mansfield-map
St Edmund (Teddy Hall): https://www.seh.ox.ac.uk/college-life
Oriel: https://www.oriel.ox.ac.uk/life-at-oriel/location/
Lady Margaret Hall: https://www.lmh.ox.ac.uk/prospective-students/facilities
Some Oxford Colleges include catering, while others do not. Depending on where you live, you may receive a partial board charge, or none.
In either case, knowing the cost of food in Oxford (the city) is helpful for preparing a budget.
Check out the website Numbeo for budget estimates:
https://www.numbeo.com/cost-of-living/in/Oxford?displayCurrency=USD