Version of asterisk

hi,

i want try asterisk open source .what is the best and new version of asterisk i can use ?
you can help me ?
thank you for a quick response.

asterisk.org/downloads

as david said download the last stable version and do the step-by-step. it’s not hard.
try first the current LTS version 11 release, and after that the 13 in beta. get involved first and read all the changelogs, it will help you to choose a version or at least show you the main differences.