Ow, srry this is dutch
in the next release it's all phrased, so you'll understand it.
For now:
U Mag geen tickets Kopen -> U can't buy tickets, you can set this per usergroup in the admincp
U hebt te weinig geld -> You don't have enough money. you can set the price per ticket per usergroup in the admincp, you also need a money system... (like ucash/ushop)
If you don't have a money system (this requires some phpmyadmin knowledge):
go to you phpmyadmin and go to your vbulletin user table.
at a column named like credits, points, money, ...
Give U are all the users something like 500 credits.
Go to you casino settings and set the cashrow to wath you have named you column.