Remove user sign in and user menu

That seems to be part of your theme. You’re using a commercial theme, so please use their official support channel. We feel they are best equipped to support their products.

https://themeforest.net/item/resido-real-estate-wordpress-theme/31804443/support

Commercial products are not supported in these forums.

It looks like this is a theme that you paid for, which was built using Elementor. So, to make changes to it, you should learn about how Elementor works. Here’s their help page with lots of learning materials.

https://elementor.com/help/

Maybe this article in particular will be helpful, since those buttons are in your header.

https://elementor.com/help/header-site-part/

Alternatively, you can ask for support from the folks who sold you the theme.

https://themeforest.net/item/resido-real-estate-wordpress-theme/31804443/support