C# Entity Framework Basics Introducing Entity Framework Adding Our First Entity Using the Code First Workflow

Is it a good practice to modify generated code from Database first?

For example, I do not always create databases in Code first. I like to design my databases in sql server and import them in Entity framework. I noticed EF generates the code for me, but what if I want to make changes? Is it good practice to modify the generated code OR just update my data via sql server?