Connecting two sites together

[Asher100]

Hi, so I'm trying to connect to network together in a strange situation, so here it is: So, we have two sights (obviously) one with an Internet connection and one with a Windows server, the one with the Internet is the House, and the other is the School. We want the users up at the house to be able to use their internet and access the server from the same wifi network. We want the users at the school to be able to use the server, but NOT the Internet from up at the house.I have a fortigate 80C, we are connection the two places together using a wifi bridge (ubiquiti) So, what I was thinking is having a certain DHCP range for the people up at the house and a different one for down at the school (probably a larger pool as well) and just using the different ranges for a policy blocking the schools range from the Internet. But I have a feeling that would be hard or impossible, can I use a VLAN? As far as I know the 80C model doesn't have proper VLAN though (at least not GUI wise). So: 1. Are the above mentioned things possible or viable with what I have? 2. How would I go about doing them if it is 3. Is there another option? I want to be able to use a dhcp server, not static addresses, that'd be annoying.