Yes, you can leave your team at any time, either by asking your coach to remove you from your team or by contacting hello@prepd.in.
Please be advised that, when leaving a team all the articles you have caught for the team will remain with them (and appear as having been caught by the coach) and you will return to the state to which your account was before joining the team. If you are part of multiple teams, leaving one of them will not affect the rest.