No such thing as a stupid question.
If you plug in a machine at home, it is behind the router, and behind the router's firewall.
If you want more of a firewall locally, something as simple as an EdgeRouter X can get you started easily with this excellent guide: https://github.com/mjp66/Ubiquiti
The nice thing about using cloudflare tunnel, is theres zero ports to expose, ever. The cloudflare tunnel app running on your local machine is what connects out to the internet and takes care of creating a secure connection between cloudflare and your machine.
If you want to forward more than one port to the machine, you could use something like cloudflare to forward to a machine on your home server, and then have the nginx proxy manager or something send the traffic around internally.
It's totally fine to start with cloudflare, and if you aren't already, something like Proxmox (youtube tutorials are pretty quick) gets you up and running and playing pretty quick. Feel free to ask any other questions you like.