GNOME is the default Desktop in Ubuntu 17.10. Ubuntu 17.10 has dock using dash to Dock GNOME shell extension. It makes the environment to look like unity.
Just perform a server test by clicking on Select Best Server and you will get the server closest to your location. This helps in downloading packages faster.
The release may not be up to date. There might be new updates waiting to be installed. Just perform this command :
sudo apt-get update
Install all your proprietary drivers so your devices can run smoothly and efficiently.
Ubuntu has a already installed firewall without a graphical interface and it is inactive by default. Though you can control the firewall from CLI but, graphical interface may be better for ease. You can install GUFW, a graphical interface for UFW (Uncomplicated firewall).
Though the default browser in Ubuntu 17.10 is Firefox but you can install your favorite web browser like Chrome.