I need a way to backup entire After effects Package

While not AE specific, if you're a Mac user,  there's a progam called Carbon Copy Cloner you can use to make an exact clone of your entire HD ,  so if anything happens to your main computer,  just connect thaat drive up to a new Mac and use Migration Assitant and you'll have a complete recreation of your original system.   perhaps ther'es similar for folks on Windows. 

I don't know about Mac but for Windows here's everything I can think of. Keep in mind these are the defaults so some of them could be different on your system. 

UI / Preferences / Workspaces:
C:\Users\<USERNAME>\AppData\Roaming\Adobe\After Effects\

Shared Adobe Settings / Licensing / AME Links:
C:\Users\<USERNAME>\AppData\Roaming\Adobe\Common\

Scripts / Presets / Templates:
C:\Users\<USERNAME>\Documents\Adobe\After Effects <version>\
C:\Users\<USERNAME>\Documents\Adobe\After Effects\

MOGRTs:
C:\Users\<USERNAME>\Documents\Adobe\Premiere Pro\

Local App Data / Media Cache / Temp:
C:\Users\<USERNAME>\AppData\Local\Adobe\Common\
C:\Users\<USERNAME>\AppData\Local\Adobe\After Effects\

Third-Party Plug-ins (Global):
C:\Program Files\Adobe\Common\Plug-ins\
C:\Program Files\Common Files\Adobe\Plug-Ins\

LUTs / Color Management:
C:\Program Files\Adobe\Common\LUTs\
C:\Users\<USERNAME>\Documents\Adobe\LUTs\

Fonts (Non-Adobe):
C:\Windows\Fonts\