Assuming you use one of the nose cone shapes suggested by rharshberger, the shape of the nose is probably the least of your concerns in determining altitude. It does make a difference, but other factors will have a larger impact. Among the critical factors are the mass of the rocket, the level of workmanship in assembling the rocket, the motor you use, the quality of your fins, etc.
Some TARC teams have been working together for several years and have experienced mentors. If you are just getting started on a design you are seriously behind the power curve since you have to have results turned in by March 30th. I hate to sound discouraging, but you are very late to the party, so you shouldn't expect much form your efforts this year. Maybe you should view this as gaining some experience to do a better job next year.