You just create a new project - if you are on the current Ionic CLI version (2.2.3, check by running ionic --version on the command line) this will automatically create a project with the current Ionic Angular/Framework version (3.0.1).
The CLI and Framework are two pieces of software. The CLI is global for all projects on your computer, but the Framework version can be different in any project you create.
So to answer your questions:
Create a project with a current CLI.[quote=“sioessi, post:1, topic:87932”]
If I install this version, can I still work with v1 on my other projects?
In older versions of the CLI you could use --v2 to create a current version project.
But you should definitely update your CLI to the current version if you want to continue developing Ionic projects (use npm update -g ionic to do so).