uportal layout ...from france

Hello, From FRANCE.
I'm a newbie with uportal.thanks for help so.
I have setting up a portal which works fine, I have published some channels, and wants to customize it now.
My Problem :
I want to have a left-menu in my portal for navigation, like sakai (I've seen https://ctools.umich.edu/portal for exemple) , and I don't know how to do ?
For the moment I can publish channels with no interaction, so how to setting up a left-menu, which can open some channels on the right side ?
Is someone can give me some exemple, some howto ?
Thanks for help.
Christophe Dumonet, from France.