Spirit Airlines is known for its ultra-low-base fare service. The base fare only includes a seat and one personal item but  for getting additional services like preferred seats, checked and carry-out baggage, etc. One has to pay some extra price. Apart from that there are so many methods through which one can make reservations with Spirit Airlines like:

Visiting the Official website of Spirit Airlines: Go to Spirit Airlines' official website by using your preferred browser navigate My Trip page to search flights enter the departure and arrival cities, travel dates, and the total number of passengers that are visiting. If you are stuck at any step contact the customer agent of Spirit Airlines by using this number +1 202-684-3533.

Use Spirit Airlines Mobile App: Download the Spirit Airlines Mobile App on your Mobile Device and navigate the “My Trip” page to search for flights and you can book flights according to your schedule.

Contact Customer Care Agent: One can Contact the Customer care Agent through the mail or by dialing this number +1 202-684-3533.

Visiting Ticket Counter of Spirit Airlines: If you are not able to make an online booking you have another option also which is booking through the airport directly. But for that, you have to pay fees for getting boarding passes.

to solve just open file public_html/storefront/controller/pages/checkout/guest_step_1.php
find method _validate ( line 632)
You need to replace
        if ($data['country_id'] == 'FALSE') {
            $this->error['country'] = $this->language->get('error_country');
        }

        if ($data['zone_id'] == 'FALSE') {
            $this->error['zone'] = $this->language->get('error_zone');
        }
with this
       if (!$data['country_id'] || $data['country_id'] == 'FALSE') {
            $this->error['country'] = $this->language->get('error_country');
        }

        if (!$data['zone_id'] || $data['zone_id'] == 'FALSE') {
            $this->error['zone'] = $this->language->get('error_zone');
        }

This is indeed a great idea for an extension! Since there isn't an existing extension that meets your needs, it might be best to hire a developer to create a custom solution for you.

I have been trying to figure out how a customer can preview their uploaded image in the product section before placing their order so they know it is the right image they want on some of my personalized items as well as the check out page, but cannot figure out where to initiate the script for it. I can do it adding a script to the page itself using a block, customers can preview their image, but it won't add it to the order because it is not part of the Abantecart image upload script attached to the actual product order form. I also cannot find an extension for it.

This just started I'm I'm getting a broken page like this not sure why because I didn't do any code changes or anything. See if you can replicate this problem and my customers are emailing me with this problem