With respect , you have a lot to learn but this forum is not the places to expect anyone to teach you, spend a few hours with a basic linux ‘bash’ tutorial then you will better understand users and ssh, then a few with the wiki here
and you will better understand Asterisk, FreePBX and how to script them, then a few more with a good python tutorial so you know how to write python scripts, having done all that here are several asterisk python AGI libraries available with a quick google search.