How do I fix the following code so there isn't an error in printing-- printing sentence but not allowing for user response?

//import java scanner
import java.util.Scanner;

//define variables
class Main 
{
  //defines variables
  String star1 = "twinkle, twinkle, little star";
  String star2, star3, firstName, lastName, password, sentenceInput, word, word2, pigWord;
  int lastNum1, lastNum2, sentTotal, sentNum;
  char character, firstLetter;
  Scanner scan = new Scanner(System.in);

  //this will run all the main methods
  public void runProgram()
  {
    twinkle();
    sentence();
    name();
    pigLatin();
  }
  
  //creating method twinkle
  public void twinkle()
  {
    System.out.println("Here is the original phrase: \n" + star1);
    star2 = star1.replace('t','c');
    star3 = star2.replace('w','r');
    System.out.println("\nThis is the phrase after replacing the T's with C's and the W's with R's: \n" + star3);
  }
  
  //creating method sentence
  public void sentence()
  {
    System.out.println("\nPlease enter a sentence:");
    sentenceInput = scan.nextLine();
    sentTotal = sentenceInput.length();

    System.out.println("The amount of characters in your sentence is: " + sentTotal);
    System.out.println("Please enter a number below " + sentTotal + ":");
    sentNum = scan.nextInt();

    character = sentenceInput.charAt(sentNum);

    System.out.println("The character you chose was: " +  character);
  }
  
  //creating method name
  public void name()
  {
    System.out.println("Please enter your first name:");
    firstName = scan.nextLine();
    System.out.println("Please enter your last name:");
    lastName = scan.nextLine();

    firstName = firstName.toUpperCase();
    lastName = lastName.toUpperCase();

    lastNum1 = lastName.length()-3;
    lastNum2 = lastName.length();

    password = firstName.substring(0,3) + lastName.substring(lastNum1 ,lastNum2);
    System.out.print("Here is your default password: " + password);
  }

  //creating method pigLatin
  public void pigLatin()
  {
    System.out.println("Please enter a word that starts with a consonant:");
    word = scan.next();
    
    calculatePig();
    System.out.println("This is your word in pig latin: " + pigWord);
  }
  
  public void calculatePig()
  {
    firstLetter = word.charAt(0);
    word2 = word.substring(1);
    pigWord = word2 + firstLetter + "ay";
  }
    
  public static void main(String[] args) {
    Main prog = new Main();
    prog.runProgram();
  }
}