You should get the decision within 90 days from when the case is submitted
After both sides have filed all their briefs and had oral argument (or the date for oral argument passes, if everyone waives oral argument), the case is "submitted." If there is no oral argument, the case is submitted at the same time as if oral argument had taken place. That is why asking for oral argument does not delay the case.
After the case is submitted, the court does not accept any more information about the case. The judges have 90 days from the date the case is submitted to decide the appeal. The clerk of the court will mail you a notice of that decision.
If you lost the appeal
If you disagree with the court's decision, you have options after losing an appeal. You will need to decide what you want to do quickly as there are strict deadlines.
If you won the appeal
Generally, if you win a civil appeal, you are entitled to have your costs paid by the other side (unless the court orders otherwise). You will need to file a memorandum of your costs in the trial court (see Cal. Rules of Court, rule 3.1700). You may also be able to ask for your attorney fees if an attorney helped you with your case. You should ask your attorney about this.
Generally, the decision becomes final in 30 days
The appellate court's decision will become final in 30 days unless any of the parties disagrees with the opinion and files a certain kind of petition to challenge it. If that happens, the court's opinion is not yet final. When the decision is final, the court will issue a "remittitur." A remittitur provides notice that the court’s decision is final and the appeal is over, and says if any party is allowed to recover some of the costs from the appeal. It also returns jurisdiction (legal power over the case) to the trial court so the lower court can follow up on what, if anything, still needs to be done to carry out the decision or decisions made by the appellate court.