My solution and possible code improvements

// 1. Create a multidimensional array to hold quiz questions and answers
const quiz = [
    ['How many planets are in the Solar System?', 8],
    ['How many continents are there?', 7],
    ['How many legs does an insect have?', 6],
    ['What year was JavaScript created?', 1995]

];

// 2. Store the number of questions answered correctly
function getUserAnswers(question) {
    const userQuestion = parseInt(prompt(question));
    if ( userQuestion ) {
        return userQuestion;
    } else {
        throw new Error('Incorrect input\nincorrect Inputs: "One", "Two", "dsadas", "41a2"\ncorrect Inputs: 1, 2, 3, 4, 5, etc...');
    }
}

const userAnswers = [];

for (let i = 0; i < quiz.length; i++) {
    userAnswers.push(getUserAnswers(quiz[i][0]));
}

/* 
  3. Use a loop to cycle through each question
      - Present each question to the user
      - Compare the user's response to answer in the array
      - If the response matches the answer, the number of correctly
        answered questions increments by 1
*/
function collectAllAnswers(arr) {
    const collectedAnswers = [];
    for (let i = 0; i < arr.length; i++) {
        const checkAnswer = quiz[i].includes(arr[i]);
        collectedAnswers.push(checkAnswer);
    }
    return collectedAnswers;
}

function countPoints(arr) {
    let pointsGained = 0;
    for (let i = 0; i < arr.length; i++) {
        if ( arr[i] ) {
            pointsGained += 1;
        } else {
            console.log(`Bummer, question #${i + 1} was incorrect!`);
        }
    }
    return pointsGained;
}

const pointsGained = countPoints(collectAllAnswers(userAnswers));

// 4. Display the number of correct answers to the user

function printMessageToHTML(message) {
    const selector = document.querySelector('main');
    return selector.innerHTML = message;
}

const correctQuestionAnswered = collectAllAnswers(userAnswers).filter((arr) => arr === true );

printMessageToHTML(`<h1>TYou got <strong>${pointsGained}</strong> points.</br>
                    and you got <strong>${correctQuestionAnswered.length}</strong> correct question(s).</h1>`);