How to determine the version and edition of SQL Server and its components

Using query command:
Select @@version

for more info read https://support.microsoft.com/en-us/kb/321185

How many clustered indexes can be in one table?

One clustered indexes per table. 

For more info: https://msdn.microsoft.com/en-us/library/ms143432.aspx

Start SQL Service from Command Line

Sometime open Microsoft SQL Server Studio on local machine, it cannot open the local databases instance, instead of using the GUI, using the command line must more quicker.

net start SQLSERVERAGENT

For more info, see
https://msdn.microsoft.com/en-us/library/hh403394(v=sql.110).aspx#CommandPrompt