For a web server, you can set up Apache. Maybe Tomcat?
For networking, configure a DHCP server and DNS server. Also, set up a firewall. Also, get some sharing set up between clients and the server. Configure samba so that windows clients can also access the server.
You can also setup LDAP.
I would recommend taking it one at a time. Install one, configure it. Then, change the configuration and play around to see how different settings affect the service. Also, with something like a firewall, see how different settings affect the other services that rely on network access.
Make sure this server is on an isolated network. You wouldn't want services you are running on the server to interfere with a larger network (such as that of your school).
These are just some ideas. I would go for the networking stuff and the web server first. Don't bother with LDAP or anything like that right away. Also, don't bother with the development environments as servers shouldn't really be running those anyway. When you get to that point, try and develop a test application on a workstation and deploy it to the web server.