SEO Titel and Meta description not changeable

Hello together,

I´m new in the wp-world and I already installed the yoast seo plugin. When I go in the sidebar under representation in search and in the register general there I can set the homepage seo titel and meta description.

At the moment under the seo titel is the variable Titel of Website, Site, separator, slogan setted. I have the problem that I can´t change them. When I delete this variables and set a new setup and go on Save, the old one comes back and the seo title is not updated. What can I do here to update this?

The same is in the meta description. There I have the problem that I want to add the html code for emojis. One times it will work. For other 2 emojis it don´t work. What can I do here?

I have already searched the forum and google and found no solution to the problem

WP Version: 6.1.1
Yoast SEO: 19.10

Many thanks for help!