Making a copy of existing site, and moving it to different tomain

I have an existing site, https://www.giannisbrickpizza.com and I want to make a copy of this site, themes, menus, and the like onto another website https://www.giannisnypizza.com. I tried to create a fresh installation of wordpress on the new domain, and then copy the wp-content folder, and import from the old site, but it doesn’t work completely. The new site is installed at https://www.giannisnypizza.com/wordpress and it seems that the menu isn’t working properly. I don’t know what I did wrong, but I would like to know the best way to do this.

Thanks,
Zach