I do not have a redmine url… Where/How can I get it?
It is an open source and free.
However, you should install it in your own server or buy some cloud service.
This is one-click install solution for Redmine:
https://bitnami.com/stack/redmine
This is the tech installation documentation for Redmine:
http://www.redmine.org/projects/redmine/wiki/redmineinstall