I am unable to target the stores that are closest to my company as they are not coming up in the interests section. The businesses that are closest to my own would be stores like huckberry.com or taylorstitch.com which is another Shopify store although it is fairly big with a large Facebook following 50k+. How can I target these audiences although the FB pages don't show up in interests or what other businesses should I target instead?
The last question I have, is there any way to see the demographics of a certain page if they don't show up in the interests section?
If the stores you want do not show up in the interests section you could do competitive keyword research instead. From here you can define the audience and target.
Yes, you can get the demographics but from outside of Facebook.
There are a variety of ways to approach this. In the beginning, much of this can seem overwhelming and quite a daunting task. Five Years ago I was in the exact same place that you are in today.
If you allow me to have a look at your site, I will gladly do a free audit and give you specific insights to help you improve your current situation.