Homelab Cybersecurity Idea

I have an Secondary PC that I don't know what to do with until I come across homelabbing.

I need idea for someone who are in Cybersecurity field.

The specs are

CPU : 2x Xeon X5675 3.06ghz RAM : 4x8gb ddr3 1333mhz Storage : 3x 1TB Seagate HDD : 240gb kingston SSD GPU : Zotac GTX1080

Any idea is kindly appreciated. Thank you so much.