It's perfectly normal to expect someone to pay the penalty before appeal. After all, we jail convicted murderers and thieves pending their appeals, too. In terms of fines, it also restricts individuals dicking around with their money to try to deny it (spending it, or finding wheezes to conceal it, etc.)
Appealing is not strictly dependent on paying - appeals are (should be) inviolable legal process. Denying appeals would be stupid and outrageous. So stupid and outrageous, had you applied some common sense you'd realise that's obviously not how it works. Jurisdictions have systems to cater for situations where individuals have problems paying.
One of these is NY's bond system, where the individual can put a security up in place of paying the fine. This is what Trump was busy doing. Whether he put up a bond or not would not affect his right to appeal, but if he did not put up a bond he would be liable for the full fine. If he paid the fine and won the appeal he would then need to claim the fine value back as compensation. Hence why the bond is an attractive option, especially where the fine might require the liquidation of assets which would then be unrecoverable.
The situational problem here being that the fine/bond sum was huge, and Trump seemingly (but see below) did not have sufficient "cash" to cover it himself, or to satisfy lenders who do not like using real estate as collateral.
Hence the the appeals court reducing the burden of the bond, on the eminently reasonable basis that Trump could not borrow such sums without having to liquidate assets that he might not be able to recover in case of a successful appeal. I will leave aside the issue that Trump claimed he had liquid assets to cover the bond and then claimed he need to arrange a loan without liquid assets to cover it, indicating he - as usual - lied.
This seems fine (heh)...
...so perhaps you should try understand more of the process before demeaning others from a place of ignorance.