Here are the events that a Facebook pixel can track:
Purchase: When someone completes a purchase on your website.
Lead: When someone signs up for a trial or otherwise identifies themselves as a lead on your site.
Complete registration: When someone completes a registration form on your site, such as a subscription form.
Add payment info: When someone enters their payment information in the purchase process on your website.
Add to cart: When someone adds a product to their shopping cart on your site.
Add to wishlist: When someone adds a product to a wishlist on your site.
Initiate checkout: When someone starts the checkout process to buy something from your site.
Search: When someone uses the search function to look for something on your site.
View content: When someone lands on a specific page on your website.
Contact: When someone contacts your business.
Customize product: When someone selects a specific version of product, such as choosing a certain color.
Donate: When someone makes a donation to your cause
Find location: When someone searches for your business’s physical location.
Schedule: When someone books an appointment at your business.
Start trial: When someone signs up for a free trial of your product.
Submit application: When someone applies for your product, service, or program, such as a credit card.
Subscribe: When someone subscribes to a paid product or service.
Even if you are not doing any ad right now, you should install the Facebook Pixel at your website or funnels. So that you can use the data later and build up that super targeted audience which are likely buy your product or service.