Once the products are in the system they can be activated or deactivated.
One way is by going to Inventory > View Product or View Variant, select product or products by clicking the check box on the left, then click the Bulk Actions drop down to see the options to activate or deactivate products.
Another way to change the status is by clicking on the product in View Product or View Variant and change the status within the product screen.
View Product Screen:
View Variant Screen: