If statement and input output

I believe you want to convert the variable yourTickets to a double so you can compare it to the variable minimumAmount. You can use the Double.parseDouble() method for that. I recommend reading about comparing Java objects and data types:

http://docs.oracle.com/javase/tutorial/collections/interfaces/order.html

You shouldn't be comparing a String type with a double type. Furthermore, you have to use .compareTo() or .equals() for Strings where as you can use >, <, >=, <=, and == for double.

Using if statements i then want the output to be either.. ''Well done you have sold enough tickets'' or ''You should really of sold more tickets'' something like that. This is what i have so far...

You need an if/else statement for this.

import java.util.*;
import java.io.*; 
import javax.swing.JOptionPane;

public class ticketjava
{ 
    public static void main(String[] args) throws FileNotFoundException 
    {

        Scanner inFile = new Scanner(new FileReader("C:\\TicketGoals.txt"));

        double minimumAmount; 
        double goodAmount;

        minimumAmount = inFile.nextDouble();
        goodAmount = inFile.nextDouble();

        String yourTickets;

        yourTickets = JOptionPane.showInputDialog("Enter your tickets sold:");

        //you need to convert the String to a double
        //this will make it comparable with ">" in the below if statement
        double converted_yourTickets = Double.parseDouble(yourTickets);

        //added if/else
        //if condition A is true then do the follow...else do something different
        if (converted_yourTickets > minimumAmount){
            JOptionPane.showInputDialog(null, "Well done you have sold enough tickets",  JOptionPane.INFORMATION_MESSAGE);
        }
        else{
            JOptionPane.showInputDialog(null, "You should really of sold more tickets",  JOptionPane.INFORMATION_MESSAGE);
        }

        //close the file before doing system.exit(0)
        inFile.close();
        //but im not sure why you have it in the first place...
            //System.exit(0);

    }

}   

You seem new to Java, I recommend the following readings of if/else:

http://docs.oracle.com/javase/tutorial/java/nutsandbolts/if.html

And data types:

http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html