You should set a password for the root account. Type:
passwd
Then enter the new password in the prompts (No characters or *'s will appear as you type your password but it IS being entered).
Unix systems always run the clock using UTC time (sometimes named as Greenwich time). You should adjust the timezone setting to have the dates shown by utilities to be like your wall clock. Type:
echo export TZ=Europe/Amsterdam>/etc/rc.timezone
Of course, you should adjust Europe/Amsterdam according to your location. You can look into the /usr/share hierarchy to find the correct name; the general principle is 'continent'/'city' or 'ocean'/'city', where 'city' is the English name of the biggest city in the same timezone as you, in the same country since timezone rules have a strong tendancy to vary according to national rules.
Always logging in as root is usually a bad idea, so it is highly recommended to set up at least one other user as soon as possible. For directions on how to do that please see: Managing User Accounts
By default, Minix runs a DHCP client at boot time, to request an IP address from your DHCP server. In this case, typically you will not know what the IP address will be and so providing a host name for the system has no functional purpose. But, if you arrange for your DHCP server to always assign the same address to your Minix system, based on the machine's MAC address, then naming the Minix host has a real purpose, e.g., you can ssh to it from another machine on your network. The same is true if you disable the running of the DHCP client at system initialization time and instead manually assign a static IP address (see boot(8) for more information). So if you know what the IP address will be and wish to assign a name to your Minix host, enter the address/name pair into /etc/hosts (see hosts(5) for specific information about the format of that file).
To install a new binary package please see: Installing Binary Packages
Some of the most commonly installed packages include:
Install the binary package for X11 using the above directions for installing packages and then see: Introduction to X