A tough one for a newbie, you need to build asterisk with chan_console support (few distro’s do)
from the asterisk cli
help console
will give you your options if any, if you get a response, then chase them down with
console list available
If not then you don’t have the module built or loaded and you will need to rebuild asterisk with chan_console support.
(this will take a long long time on a PI)