If you want to connect to SQL server remotly you need to use a software – like Sql Server Management studio
Follow these Instructions:-
Start SQL Server Browser service if it’s not started yet. SQL Server Browser listens for incoming requests for Microsoft SQL Server resources and provides information about SQL Server instances installed on the computer.
Enable TCP/IP protocol for SQL Server 2008 Express to accept remote connection.
(Optional) Change Server Authentication to SQL Server and Windows Authentication. By default, SQL Server 2008 Express allows only Windows Authentication mode so you can connect to the SQL Server with current user log-on credential. If you want to specify user for connect to the SQL Server, you have to change Server Authentication to SQL Server and Windows Authentication.
Further study this link:-https://www.linglom.com/it-support/enable-remote-connection-on-sql-server-2008-express/
solved How to connect my project to the sql Express on another pc?