If you do not own a car and you are not going to be driving someone else's car regularly, you can get a non-owners policy.
A non-owners policy will allow you to drive any car. It will only cover you for liability. It will not cover the car you are driving. If you are going to be driving someone else's car regularly (more than once a month) the owner of that car will need to add you as a driver to their policy. Good luck and if you have any other questions, don't hesitate to ask. Here
is some general information you can find regarding car insurance.