I have the educational version of Tekla but the UK environment for steel sections is not loaded, some other sections are listed, I think that they are European so I cannot follow the manual.
You can download the UK environment from the "Download" page (https://campus.tekla.com/download) scroll down and click on "additional environment's." For all the lessons on Tekla Campus we are only supporting the default environment (not specific country code environments).
Are you an educator? See options for institution licensing.