Having a hard time trying to figure out what to do with this code for coin flip with a betting system

I have looked all over this website and other websites trying to figure how to do this with the knowledge that my teacher has provided me.

Basically the program is supposed to be a user input system where you can make bets on a head or tails coin flipping game.

So far, I've had no luck in what to do. Not asking someone to finish it for me, but to help me in the right direction.

Thank you in advance.

Here is my code so far:

package Homework6;

import java.util.Scanner;

import java.lang.Math;

public class CoinFlip {

        public static void main(String[]args){
        
        Scanner input = new Scanner(System.in);
        int money = 10;
        double flip = Math.random();
        String heads = "heads";
        String tails = "tails";
        int bet = input.nextInt();
        
        while(bet < 0 || bet > money){
                if(true){
                        System.out.println("How much do you want to bet?");
                        input.next();
                }
        }
                
        System.out.println("Guess if the coin will be heads or tails.");
        String guess = input.next();
        
        String coin;
        if (flip <0.5) coin = heads;
        else coin = tails;
        
        if(guess == coin){
                int correct = money + bet;
                System.out.println("The flip was"+ coin);
                System.out.println("You win" + bet);
                System.out.println("")
                }
        
        
        
        
        
        }
}