How long can I use the free trial before purchasing the server edition?
There is no time limit. Evaluate as long as you require.
@lubos Do you mean evaluating with desktop version ?
I am running a school, I need to generate fees invoices and fee receipt for
Pls which module is suitable for that purposes?
You would use the Customer & Sale Invoices tabs to generate fees invoices
And Cash Account tab with Receive Money for fees receipt.
You can also do Receive Money via Sales Invoices