All people receiving the sacrament of Confirmation are to take the name of a Saint or biblical figure that is special to them and relevant to their life. Some people choose the name of a saint that is a patron of a particular activity or career, like St. Florian, the patron of Firefighters, or St. Sabastian, the patron of athletes, or St. Cecilia the patron of muscians. There is a special bond between you and your chosen saint.
If your baptismal name is a saint, like "Mary" or "John", you may chose to use your baptismal name as your Confirmation name.
Therefore, since we are surrounded by so great a cloud of witnesses, let us rid ourselves of every burden and sin that clings to us and persevere in running the race that lies before us while keeping our eyes fixed on Jesus, the leader and perfector of faith. (Hebrews 12:1-2)
You may chose your baptismal name (your first or middle name), but only if it bares relationship to a Saint or biblical figure's name. Choosing your baptismal name demonstrates that you feel there has been a continual growth in your faith and that you now wishh to make this formal through Confirmation and First Eucharist.
The second option is to choose a saint's name that symbolizes a new beginning in your faith life and a connection to that particular saint. The taking of a new name symbolizes this commitment to follow Christ.