What project ideas are there for a cybersecurity homelab?

I apologise if this question feels like a repetition on this subreddit but every post I have found relating to it is vague, in the sense that answers mostly consist of making VM containers but never continuing with the objectives with it e.g do I hack it (a random VM) with a kali environment? What do I do with pfsense? Do I have to buy it for real? Do I also need a VLAN?

**My Current System**

Main PC with …

containers cybersecurity hack homelab ideas making objectives project question random repetition