Add existing Webpage to wordpress

Use text editor option for when adding pages and posts….get a plugin that supports what you’re wanting…most of the time all of this is located within the side menu in admin panel e.g. themes>>Css you also need an external html editor or something similar and save those files on your computer then upload via a file importer plugin… codex.www.remarpro.com is a good site for any other help you need!