Configure juniper ns-5gt (Firewall, VPN & DHCP Server)

Hi,

I need help configuring an existing Juniper ns-5gt in a our new office. The IT there gave us an network port to be able to connect to the internet. Internet can now be established on our 9 PCs through a switch by assigning static IP addresses to each PCs withing the given range.

Range: 192.168.44.50 to 192.168.44.70

Default Gateway: 192.168.44.1

DNS:

202.123.2.6
202.123.2.11

Internet and file & printer sharing works without problem. But I am worried about someone trying to access my PC in the network using IP addresses.

MY QUESTION: How do i need to configure the Juniper NS-5GT to be able to use it as a Firewall, VPN & DHCP Server?

Thanks a lot for your answer.