this is how you use my script
commands:
/geld to see how mutch money you has
/geldadd player to add money to a player

This script works with my scoreboard script for displaying money. If you're looking for a good scoreboard and want the money to be visible, then check out https://www.spigotmc.org/resources/skript-aurascoreboard-scoreboard-free.129896/. The scoreboard is also easy to customize like all my scripts.