Getting SQL and Window Server 2012 R2 support with Microsoft

Hi all,

I am very new to the MS environment.
I have purchase  Microsoft Server 2012 R2 Enterprise licenses and SQL Server 2014 Enterprise Licenses.

May I know where can I contact/submit Service Support Request with Microsoft should I encounter any technical or setup issue ?is there a portal or something specially for that ?

Do I need to purchase Software Assurance in order raise tickets ?

p.s. sorry if I am asking in the wrong place. please point me to the right place if possible

Thanks!