Need help with miscellaneous IT work for my home setup

I'm looking for a friendly tech person to help with a few miscellaneous IT tasks at my home in Ireland. The job includes troubleshooting a slow Wi-Fi network, setting up a reliable backup solution, configuring security basics (firewall, updates, and antivirus), and tidying up cables. I also need guidance on organizing my files and a quick tune-up of my computer to improve performance. Preference for someone who can explain things clearly, works with Windows and macOS, and can work around a flexible schedule. Please mention any tools or approaches you recommend, and whether you can do remote work for some tasks.