I want to create a program for my company that includes products and licences that we sell, they will have a start date and end date for every product that every customer is using.
I also want an automated email that sends a reminder about the expiry date of the product
with a database for the customers and the products.
There are a lot of vague things (like '..with a database for the customers and the product..') in your story. You might as well go to an architect and say 'I want you to design me a house with a door that can house a bunch of people, and also must have some glass windows'.
Yes, you can probably build something with Node Red that would fit your description.
You can do most things in Node-RED, whether you should is a different matter.
We know nothing about the size of your data or its complexity or how often it changes, how you (or someone else) will support it, how secure it needs to be, the value of the data, ...
You could certainly build a prototype with Node-RED but unless you or someone else has the skills and knowledge to build and maintain robust and secure IT systems, you are likely to need some paid help.