Laravel brings a migration from "factory" to create the users table that will be used for the user login system. If after installing the framework you create your own migration to create a users table and you do not delete the original migration when you launch migrations, one is used and when trying to use the next one, like the table users has already been created you have the error.
You can choose:
Delete the original migration if you are going to customize the login system or not use it and add yours before launching the migrations.
Modify the original migration to adjust it to your needs, before launching the migrations.
Launch the migrations first, and then create yours, keeping in mind that the migration for the users table will be to update what you need, not to create it.
Note: If you've already launched migrations, you can delete the database and start from 0, otherwise: you already have a users , check what is and continue with option 3 if the created table is the original of Laravel or eliminate the migration that Laravel brings if the one that was applied was yours, to avoid the error when launching new migrations.