Creating an instance after installing the data server client depends on the specific database management system (DBMS) you are using.
SQL Server:
Open SQL Server Management Studio (SSMS)
Connect to the server where you want to create the new instance.
Right-click on the server and choose "New SQL Server stand-alone installation or add features to an existing installation"
Follow the prompts to complete the installation of the new instance.

Oracle:
Open the Oracle Universal Installer (OUI) from the Oracle home directory
Select "Create and configure a database"
Select "Advanced installation"
Follow the prompts to complete the creation of the new instance.

MySQL:
Open the command prompt and navigate to the MySQL bin directory
Run the following command:

mysqld --initialize-insecure --user=mysql

Once the initialization is complete, start the MySQL server using the command:

mysqld
Log in to the MySQL server using the mysql client and create a new instance by running the following command:

CREATE INSTANCE 'instance_name' USING DATADIR='path/to/data/directory';