By Default VM’s created on VirtualBox come preconfigured under NAT and are assigned a default IP address. Considering you have pfsense installed and configured but your machines can’t talk to each other and don’t have internet access follow the steps bellow. To get up t this point follow Here

1.Select 2 and hit Enter.

2.Select 2 and hit Enter again.

3.Depending on your Configuration assign the LAN IPv4 address.

4.type 24 and hit Enter.

5.Hit Enter.