Your first court date is an arraignment which means you are informed of the charges against you and advised of your legal rights. You enter a plea which is almost always "not guilty" and decide whether you want a speedy trial or not. Future court dates will be set depending on how you or your lawyer wishes to proceed.
Yes you can put off the arraignment for a short time to find a lawyer but if you can't pay for one anyway why bother. The Fresno PD is perfectly capable of defending this kind of case. Give any documents you have to your PD, not the Court which won't look at them anyway.
This is a criminal matter. It is reasonable to ask for more time. If you don't feel comfortable with your public defender, then you may want to look for an affordable lawyer. A public defender will generally tell you what the offer is from the district attorney or judge. On your first court date, you will most likely plead not guilty. They will probably set a pretrial date, which is basically a date where you will get an offer on the case. The offer will probably include probation. They will want to book and release you if you didn't go to jail since this case would be used against you in the future to elevate a future theft case to a felony.
I would give your lawyer all documentation. Be careful about telling the court if you have a shoplifting problem. That's something you need to discuss with a lawyer about strategy. It can help, but it can also hurt. School grades and trying to better your life is great stuff!
If you don't have a criminal record and there was no violence in this case, I wouldn't necessarily plead guilty to this shoplifting charge. You need to have a lawyer obviously read any police report before making any decision to fight at a jury trial or plead guilty. Maybe with the good information your lawyer introduces to the court, the lawyer can negotiate a lesser charge, such as trespassing or an infraction for trespassing or disturbing the peace. Misdemeanor convictions can also have severe consequences for obtaining future employment. What good are the school grades, etc. if you can't get a job? Licensing authorities, such as nurses, etc. frown upon misdemeanor convictions. I've known people that got denied a nursing license because of a simple misdemeanor conviction.