When writing a CV for a managerial position, you must emphasise your past experience in which you have had additional responsibility. For example, if you worked in a shop and were a key holder, this proves your employer held you in high esteem and trusted you enough to have a set of keys to the store.
Don’t dwell on lower positions. Instead, highlight your enthusiasm and your ambition to progress in your career. This should be done with the intention of proving to a potential interviewer that you have what it takes to become a manager in their firm.
As with all formal communications, use proper language and be polite and formal in your writing. However, do not be afraid to let the language reflect a little of your personality. This person should find you interesting and want to know more about you. There is no harm in keeping a little to yourself though, in fact I would recommend it.
Good luck in your applications.