Text underlined, but why?

Are you running Grammarly on your own PC? I use that myself and I spell really horribly and type with a ‘southern accent’ so it is constantly nattering at me to correct my spelling and grammar.

Kind of a good thing in my estimation.

Hi @kaanekici,

You can try to override the MSO CSS.

a:link, span.MsoHyperlink {
    text-decoration: none !important;
}

How to add custom CSS to WordPress

https://medium.com/@marklchaves/adding-custom-css-to-your-wordpress-website-how-to-guide-a50b474af36d

In the future try to avoid copy/pasting from external editors into the visual tab.

Good luck!