Traffic Shaping Dormitory Setting

[opnn03l]

I'm fairly new to OPNsense. What I'm really interested with is traffic shaping. I tried using pfSense but whenever I try to use traffic shaper it would give me an error and effectively disables our internet connection.

I have tried other commercial gateways like wingate and kerio but they are very cost prohibitive and bulky to configure. I also tried custom firmwares like openwrt and dd-wrt but they run on legacy routers already and sometimes they just can't cope with high demand and latency. Often times they would hang and I had to manually reboot them.

So basically this is the setup:

A dormitory that maintains a huge network of 100 or more computers connecting to the internet.

With traffic shaping in mind, how can I share equally 3 mbps of download and 0.86 mbps upload to at least 15 concurrent users without too much latency or lag when browsing?

I want to also allow P2P to a bare-minimum and other services like gaming in the future but what's important now is to make browsing seamless and responsive.

Our test hardware:

AMD 1640 2.7 GHZ single-core
2 GB RAM
30 GB HD
1 WAN
1 LAN

I'm open to suggestions so please don't hesitate to mention any.