Assuming a genuine newbie question, carbon fibre a a great material for play bikes but does less well in bikes that have to earn a living as commuter rides, the material is soft and can be scratched by careless people at the bike lockup. Attaching luggage racks is often difficult.
If carbon is what you want, the next questions are
What size
What riding position
What tyre clearance
What brake style ( disc for all weather use)
What gearing.
A full on elite race bike may not be the best option if your rides are less athletic and over hilly terrain.
As Jonny5 said in the motion picture Short Circuit: "Need Input'.