I completely understood that you would like to allow your visitors to edit the content from the frontend but WordPress by default will not provide this type of options because this will break your entire site security as anybody will come on website and update any content that is not right for your website
Further, There is way to allow the authorize user to add/edit the content from the website where your visitor need to create the account and you need to give the rights to your visitors to add/edit the content from the website frontend. There are so many Frontend visual editor plugins available that will allow your authorize customer to add/edit the content from the frontend site.
https://wordpress.org/plugins/wp-quick-front-end-editor/
Please let me know your query if you have any.