It is much easier to update your resume periodically than all at once, so even when you’re employed, set a reminder to refresh your resume every three months, while the information is still fresh in your head. This will make your next job search much easier, should you decide to switch companies or careers in the future.
There is not one resume format that works for everyone. There might not even be only one resume format for you and it could benefit you to have multiple formats of your resume available. For example, if you’re applying for a job and you don’t know whether your resume will be submitted through ATS, submit both a chronological resume and use a functional resume for your in person interview.