One question need to ask how can i call from sip to my mobile number or to my landline
You need a VOIP provider. I’m pretty new to all of this, but I use http://www.rapidvox.com/ for my outgoing calls from Asterisk and they’ve worked out great so far. Basically they terminate your sip call to an actual phone line.
Google “VOIP provider” and do a lot of research, some are good, some not so much… and prices vary widely.