Newcomer Starting Problems

I’ll start with Asterisk but I’m not able to setup a dialplan for 3 phones for work.
Asterisk runns and I tried to debug the messages but I do’nt understand whats wrong.
Has anybody a few minutes and “Lust” to see into my server and correct my mistakes ?

I would give an acces to my server (has an public IP too second network card)

Have 3 phones nr100, nr101, nr 103 (SIP Phones) with fix IP’s
and i’d like to connect local between them.

Post the relevant config files. extensions.conf, sip.conf, and anything else you have modified.