You can set up your user packages to use CLIM as follows:
(in-package :user)
(defpackage "FOO"
(:use :clim-lisp :clim ))
The package :clim-lisp is a version of the :lisp package that shadows some of the Common Lisp symbols. The :clim package is the exported CLIM interface.
Common Lisp Interface Manager 2.0 User's Guide - 7 Aug 2017