Depends... There are many COPD inhalers that can be prescribed so it is difficult to answer your question without knowing the inhaler that was prescribed. But, follow the instructions on the inhaler you got at the pharmacy. If you are still unsure, call your doctor who knows what inhaler you are taking.
Medication specific. It really does depend on which specific medication you are taking. Some inhalers are rescue inhalers (like albuterol or xopened) that can be used multiple times throughout the day as needed. Other inhalers are long acting (like spiriva, advair, symbicort, (budesonide and formoterol) etc) that have specific dosing for the day and should not be taken more than directed. Get specific instructions from your doctor.
What your doc says. The types of medications and the number of times those medications are used are very patient specific. This is a question best answered between you and your personal physician. There is no "one right answer" for everyone on this.