Hi:
If you are new to forecasting, perhaps the easiest way to get started is to use a point-and-click interface which will guide you through the analysis, modeling and forecasting.
SAS Studio provides a point-and-click interface for generating SAS code and it includes forecasting tasks since release 3.4. It is available for free if you have SAS 9.4 or newer.
This page has general information about SAS studio.
http://support.sas.com/software/products/sasstudio/faq/index.html
This page has documentation regarding SAS Studio and the forecasting tasks.
http://support.sas.com/documentation/cdl/en/webeditorug/68254/HTML/default/viewer.htm#n0zupbjif1khpg...
I would recommend that you watch the tutorial videos about time series overviews:
http://support.sas.com/training/tutorial/studio/time-series-overview.html
And time series modeling and forecasting:
http://support.sas.com/training/tutorial/studio/time-series-modeling.html
If you are using an older release of SAS and don't have access to SAS studio, or you want a purely point-and-click interface, you can use the Time Series Forecasting System. You can find an overview here:
https://support.sas.com/rnd/app/ets/cap/ets_forecasting.html
I hope this information helps to get you started.