First you should note, creating a Session
instance means not creating a real php session. A php session is already created during fetching the request and you have to use this object.
So in your controller:
$session = $request->getSession();
$session->set('name', $user->getFname()." ".$user->getLname());
$session->set('uname', $user->getUsername());
$session->set('pwd', $user->getPassword());
And in twig the session is accessible via app.session
.
{% set sessionName = app.session.get('name') %}