Grounds for an appeal? There are no factual ones but your Orange God will try and state there were legal errors made during the trial, create some constitutional issues, or claims of procedural irregularities within the case itself.
The process for an appeal would typically involve filing a notice of appeal with the court, followed by the preparation of appellate briefs outlining the arguments for appeal.
Trump's legal team would likely focus on trying to fabricate a fictional case based on the grounds for appeal, and they would present their arguments before the appellate court. If successful, the appellate court may overturn the original decision, order a new trial, or modify the original judgment.
As for my opinion, he's guilty of 34 felonies. I don't think there's any way he does jail for this but I do think he was tried fairly and justly. He does deserve a stiff punishment.