You have two basic choices when it comes to legal representation:

a) hire your own attorney;
b) let the court appoint an attorney to represent you.

Technically there is a third choice: to represent yourself, but that is not worth considering when your whole future is at stake.

Relying on the court to appoint an attorney is like playing Russian roulette; you have no way of knowing what kind of lawyer would be appointed, you could end up in jail if the court appointed an inexperienced lawyer.

Hiring the right lawyer is essential if you want to have:

a) a chance of avoiding a prison sentence, or
b) the minimum term if a prison sentence is unavoidable.

Standing trial could be the most important event of your life (as well as one of the most frightening); you need to make sure you have the best possible legal representation.

The right lawyer can help you to get the minimum sentence, so you have less time to survive in prison.