Nick here from Shopify. Great question!
There a few good subscription apps in the Shopify app store which you can choose from for a subscription feature. Let's look at the most popular Subscription apps in closer detail below:
Each app would be slightly different in function and cost. But from what you have mentioned in your post, it seems like a basic function which they would all be able to do. It might be worth looking at the cheapest app to see if it can do what you need.
Hope this helps!
All the best, Nick