Adobe has many products.
One is Acrobat Reader, which at some point you will likely need to read a .pdf formatted document. This is a popular online format for manuals, documents etc. It is a safe program and you can get it free from Adobe here.
Adobe - Adobe Reader Download - All versions

The flash player is from Adobe also. You will need this to view videos from many popular website like, youtube, CNN, BBC and many more.
You can get the latest version here.
http://www.adobe.com/go/gntray_dl_getflashplayer
After you download it, and before you install close any open programs and shut down any running programs. After install don't forget to restart any anti-virus or anti-spyware programs.