Qubes requires a lot of configuring to be properly secure and you have to have a fair bit of understanding about virtualization.
I'd suggest starting with Whonix . It still uses some of the same virtualization technology, and like Tails routes everything over Tor, and provides excellent protection against threats on your local network (due to separating Gateway into its own VM)
Also Whonix is straightforward to set up. You first install VirtualBox, then literally just double-click the Whonix .OVA file to install. It fires up two virtual machines: Gateway and Workstation. You use the Workstation; the Gateway handles Internet traffic (and you generally don't login to it)
You can save files, customize your desktop, use it like a normal computer.
EDIT: just noticed this
opening risky files
For that, your best bet is a burner laptop that you re-image regularly. Qubes is also a pretty good way to do this; you'd set up an extremely locked-down execution environment for the "risky file".
But if the risky file attacks Linux-based OSes, you're hosed even under Whonix or Tails.