guys can i ask something, what kind of server or database is good for Microsoft Visual Studio 2008, or VB.net
You can integrate a variety, but Microsoft's Visual Studio integrates very easy with Microsoft SQL Server.
You can download the express edition for free. Its fully functional, just as good as their enterprise versions, except the advanced features are not supported.
You can also download (free) the SQL Management Studio which greatly simplifies the creation and management of databases. However, installing it is tricky unless you follow the step by step instructions
Can u give me a link where i can download MS Sql Server?
There really is no "best". Microsoft's SQL Server basically works out of the box I believe. But all others are pretty much compatible.
I personally always suggest MySQL/MariaDB. Very configurable (Note that this is a good AND bad thing) MSSQL is good but It just not 100% free nor open source.