If you're just looking to get into modern torrenting, start here: https://trash-guides.info/

If you're ready to put it into action, you might want a network attached storage device (NAS) to run your *-arr stack and store your stuff. I recommend a Synology NAS with at least 4 drive bays and a redundant drive.

You should do all of this behind a VPN. I recommend Proton.

My rig is set up to run in containers with docker-compose. I automated it all to the point that I just have to boot up my NAS and the torrenting starts up automatically. It's all managed through websites hosted in various containers on the NAS that I can access from any other device on my network. You can read the docker docs here: https://docs.docker.com/compose/

LinuxServer.io is also a fantastic resource for docker containers: https://docs.linuxserver.io/

Also, it's a good idea to run pi-hole for a network-wide tracker-blocker and ad-blocker. You should have your pi-hole devices on your network as a separate device that doesn't do anything else. I have 2 pi-hole devices on my network. The hardware they run on is just the smallest Raspberry Pi's I could find at the time. I connected them to the network via WiFi and plugged them in behind a dresser in one bedroom and next to the wifi router in the other room.