Scenario:If you open SQL Server Management Studio, it will ask you provide the SQL Server Instance Name. Once you do that, It opens Object Explorer. You would like to open Object Explorer and New Query window on startup.
Under the Keyboard, go to Startup and then make changes as shown below.
You have following options
Open Object Explorer
Open New Query Window
Open Object Explorer and Query Window
Open Object Explorer and Activity Monitor
Open Empty Environment
You can choose according to what works best for you.