I can't understand how to insert a photologue gallery into my web-page?
I've installed that plugin, added to INSTALLED_APPS, updated urls.py and added photos to gallery in admin, but have no idea what to write in base.html or in any other template file to start using gallery.
You'll either need to write your own CMS plugin to integrate photologue with the CMS or find something someone else has already written that might meet your needs.
Like cmsplugin-photologue-pro or cmsplugin-phlog but these are quite old so would no doubt need changes to work with the latest version of CMS.