Help with back end programming on WIX

I have already done the majority of the work. However I now need someone to fine tune it and run me through what it all means.
I need a programmer who has experience with using the back end of WIX.
The project involves generating random questions from databases.

This is the code so far:

// For full API documentation, including code examples, visit http://wix.to/94BuAAs
import wixData from 'wix-data';

// Helper function to setup the table
function setupTable(showAnswers = false, resetData = false) {
// By default we always want to show the question column
var cols = [
{
"id": "col1",
"dataPath": "question",
"label": "Question",
"type": "string",
}
];

if(showAnswers) {
// Push (add) the answer column to the list of columns if we are viewing answers
cols.push(
{
"id": "col2",
"dataPath": "answerText",
"label": "Answer",
"type": "string",
},
);
}

// Set the columns on the table itself to be our array
$w('#resultsTable').columns = cols;

if(resetData) {
// Reset the tables data back to empty ([]) if we are reseting the data
$w('#resultsTable').rows = [];
}
}

function setupDropdown() {
// Query the Test dataset for values
wixData.query('Test')
.limit(1000) // Get all values
.ascending('title') // Sort by title ascending
.find()
.then(res => {
const uniqueTitles = getUniqueTitles(res.items); // Create a list of unique titles only
let cleanList = buildOptions(uniqueTitles); // Build them in to a format dropdown understands
$w("#topicFilter").options = cleanList; // Set the dropdown to be these values
$w("#topicFilter1").options = cleanList; // Set the dropdown to be these values
$w("#topicFilter2").options = cleanList; // Set the dropdown to be these values
})

// Converts a list of items with duplicates to a list of unique items
function getUniqueTitles(items){
const titlesOnly = items.map(item => item.title);
return [...new Set(titlesOnly)];
}

// Converts a list to objects (for use in dropdown)
function buildOptions(uniqueList) {
return uniqueList.map(curr => {
return { label: curr, value: curr };
});
}
}

// Run the filter to update the table
function processFilter(filterValue) {
var promise = wixData.query('EnterpriseDB')
.limit(1000) // Get all the values - we need to do this first
.contains('title', filterValue) // Filter based on the dropdown value
.find();
return promise;
}

function runFilter() {
var dropdownFilter = processFilter($w('#topicFilter').value);
var dropdownFilter1 = processFilter($w('#topicFilter1').value);
var dropdownFilter2 = processFilter($w('#topicFilter1').value);
Promise.all([dropdownFilter, dropdownFilter1, dropdownFilter2]).then(res => {
// Copy the results and randomise them
var results = shuffle(res[0].items.slice(0)).slice(0, $w('#topicSlider').value);
var results1 = shuffle(res[1].items.slice(0)).slice(0, $w('#topicSlider1').value);
var results2 = shuffle(res[2].items.slice(0)).slice(0, $w('#topicSlider2').value);

var outputResults = results.concat(results1).concat(results2);

// Set the results table rows to be the results
$w('#resultsTable').rows = outputResults;
});

// Helper function to shuffle
function shuffle(array) {
return array.sort(() => Math.random() - 0.5);
}
}

// Called on page load
$w.onReady(function () {
// Call setup table, don't show answers, do reset data
setupTable(false, true);

// Call setup dropdown
setupDropdown();
});

// Event for when dropdown is changed
export function topicFilter_change(event) {
runFilter();
}

// Event for when answers switch is changed
export function answersSwitch_change(event) {
setupTable($w('#answersSwitch').checked);
}

// Event for when slider changes
export function topicSlider_change(event) {
runFilter();
}


See the photo attached.