How to print numeric object attributes using console?

I am a beginner in the middle of a js basics course. I have a simple object related exercise and everything seems to be working except for the numeral values where the console prints the function instead of the wanted result.

// My code -->
const pete = {

  firstname1: "Pete",
  fullname1: "Pete Programmer",
  age: 20,
  
        firstname: function() {return this.firstname1},
        fullname: function() {return this.fullname1},
        age1: function() {return this.age1}
}       
const cara = {
    firstname1: "Cara",
    fullname1: "Cara Code",
  age1: 32,
        firstname: function() {return this.firstname1},
        fullname: function() {return this.fullname1},
        age: function() {return this.age1}
}
// teachers uneditable code -->

console.log("Name: " + pete.fullname() + "tAge: " + pete.age);
console.log("Name: " + cara.fullname() + "tAge: " + cara.age);

console.log(cara.firstname + "is " + (cara.age - pete.age) + " years older than " + pete.firstname);

Console output:

"Name: Pete Programmer  Age: 20"
"Name: Cara Code    Age: function() {return this.age1}"
"function() {return this.firstname1}is NaN years older than function() {return this.firstname1}"

I havent been able to find the answer despite this looking like a simple problem.