A little background. I've had my store open for around 4 months now and have received one sale. I spent over $300 USD on Facebook advertising, I've accumulated 40 customers to my email list and any visitors I get very rarely add to cart, I have a total of 1.3k visitors to my site (Petfullyyours.com). I keep my Instagram, Facebook, and Twitter updated regularly I also run email campaigns to my subscribers and any new ones. I offer special sale events and free shipping all the time to balance out the long shipping process. My website is clean and easy to navigate I have a wide selection of products without looking overwhelming at inexpensive prices and I spent a great deal of time on descriptions. I just don't know what I need to change If anyone could take a look at my site and give advice on ADs that would greatly be appreciated. FYI I have under 100 followers on all social media the most being 75 on instagram.
If all those you have listed is true for your website then I think you are targeting the wrong audience in your ads. Target only those who are your prospective buyers and make sure your ads are highly relevant to the landing pages. Whatever you are claiming in the ads the same things should be reflected in your landing pages then only people will start buying. Also make sure you don't have any competitor who are providing those products in cheaper prices and faster delivery.
I have checked your website in Google's page speed insights and found that performance of your website is very poor for mobile devices. Check your analytics account and see if you are getting most of the traffic on mobile and tablets. Work towards making website great for even mobile devices and hope you'll get sales.
Sounds like you may be targeting the wrong people. Have you tried another platform like Google/Bing Shopping? It's usually easier to get up and running and faster to drive sales and revenue. Facebook is a great compliment to Google Shopping as well.
Are your running any remarketing campaigns? If not, you should, otherwise, you're just burning money. About 80% of people abandon products in their carts, you need to target them with Dynamic Product Ads on FB and IG as soon as they leave your store. Try some promo codes to make them come back and finish the purchase. As for Shopify stores, AdMonks is great for remarketing automation, just a few clicks and your campaign is out there, no need to get into FB Business Manager.