Your main water supply normally enters your home in the cold kitchen or utility room tap. So, if water comes out of this tap but nowhere else (such as your shower or bathroom), the problem is likely to be with your internal plumbing. In which case, you'll need to contact the agent and report the maintenance issue.
If there's no water coming from your cold kitchen tap, check your inside stop valve needs to be fully open. It's normally located under the kitchen sink, in the airing cupboard or under the floorboards by the front door. If the valve is closed, turn it anti-clockwise. Your outside stop valve also needs to be fully open.