How to setup an application to read an API and display the results in a different format in a minimal way?

I am trying to develop an application that needs to make a call to an API. Get the results and show them in a prettier format on a UI.

How my application accomplishes that right now is;

• Call the API.
• Deserialize the response to a c# object.
• Check the response object if a date field is filled, check the date field on a table in my database.
• If the API response has the date and my table doesn't, I update the date on my database.

I am aware this is very coupled to the API response and the way I save it in my database. My database table is not in the same structure as the API response because I don't want to show the data I get from the API as it is.

What is the best way to achieve this result? How to store the data from the API to make this system clean and less coupled? What are some tools I can use to achieve this? (I currently use c#/.Net, SQL Server and Angular)

A very vague question, but open to any ideas, opinions. Will be updating the question to make it more clear.