Nick here from Shopify. Good question!
There is no exact template for an FAQ page and the reason for this is because every FAQ page is different for all stores. Even if the stores are similar in nature by selling products that are alike, they might be based in different countries and have different shipping times because of that.
I think the best thing to do is start by figuring out if an FAQ page is right for you. If you think it is then it might be worth sitting down and brainstorming which questions you think your customers will care about the most. A good way of doing research for this is by taking a look at some of the FAQ pages of stores you like or would like to be like and take inspiration from all of them to make the perfect FAQ page for you. There are some apps in the Shopify App Store which could assist you with a general layout and template of sorts, let's take a look at some of them below:
The content team at Shopify also wrote a blog post called The Benefits of an FAQ page (And How to do it Right) which I think you might find useful also.
Hope this helps!
All the best, Nick