Navigate to http://www.pfsense.org/ and click on the Download section.

• Open Virtual box.
• Click New to create a new machine.
• Select Type BSD and version FreeBSD (64-bit).
• Select your RAM, 512 MB minimum.
• Provide the location of virtual hard disk location on your PC and select the hard drive file type VDI.

• Select the Setting option.
• Click on the Network option and in Adapter 1 select the option Attached to Bridge Adapter.
• Now click on Adapter 2, and select the option Enable network Adapter and select the option Internal network.

• Click on the Storage option from the cd menu select Choose a virtual CD/DVD option and point to the pfSense image file on your hard-disk.

• Click on Start to power on the virtual box machine.
• Select Option 1; Boot pfsense (default).
• It will prompt you to create a Vlan. Select No and enter em0 as WAN interface name.
• Select the option < Accept these settings >.
• Select the option < Quick /Easy install > and click on OK.
• The installation will start.

• Select the Standard kernel option.
• It will ask to reboot. Remove the Image file from the Device menu and reboot it.

• Connect to pfSense through a web browser.

https://docs.netgate.com/pfsense/en/latest/install/download-installer-image.html

https://docs.netgate.com/pfsense/en/latest/config/index.html