2015 VS -web.config?

It looks like   MS has made significant changes to the web.config file. How do you set the connectstring? And don't you have to put anything in for the Membership and Users sections?

I created a SQL Data source using a stored procedure from the database and it ran fine. but where does it go in web.config ?

<connectionStrings><add name="DefaultConnection" connectionString="Data Source=DAVE-UMW\UMD;Initial Catalog=BDUC3;Integrated Security=True" providerName="System.Data.SqlClient"/><add name="BDUCConnectionString" connectionString="Data Source=DAVE-UMW\UMD;Initial Catalog=BDUC3;Integrated Security=True" providerName="System.Data.SqlClient"/></connectionStrings><system.web><authentication mode="None"/><compilation debug="true" targetFramework="4.5.2"/><httpRuntime targetFramework="4.5.2"/><pages><namespaces><add namespace="System.Web.Optimization"/><add namespace="Microsoft.AspNet.Identity"/></namespaces><controls><add assembly="Microsoft.AspNet.Web.Optimization.WebForms" namespace="Microsoft.AspNet.Web.Optimization.WebForms" tagPrefix="webopt"/></controls></pages><!--
	      ASP.NET Membership is disabled in this template. Please visit the following link http://go.microsoft.com/fwlink/?LinkId=301889 to learn about the ASP.NET Membership support in this template
        --><membership defaultProvider="CustomizedMembershipProvider"><providers><clear/><add connectionStringName="BDUCConnectionstring" passwordFormat="Clear" minRequiredPasswordLength="6" requiresUniqueEmail="false" minRequiredNonalphanumericCharacters="0" applicationName="/bigdogs" requiresQuestionAndAnswer="false" name="CustomizedMembershipProvider" type="System.Web.Security.SqlMembershipProvider"/></providers></membership>

But it crashes wit this error:

Source Error: 


Line 25:                 // Validate the user password
Line 26:                 var manager = new UserManager();
Line 27:                 ApplicationUser user = manager.Find(UserName.Text, Password.Text);
Line 28:                 if (user != null)
Line 29: 

Any id