It’s been covered elsewhere many times, but I’ll do a quick recap:
Vålerenga Oslo. Active club member, active ultra. Season ticket and as much away travel as I can financially and logistically swing.
Then I have a couple of teams I follow closely, but not religiously, like Celtic and St. Pauli, and more recently and to a smaller extent, Athletic Club. I tend to have soft spots for teams that are part of the left wing/antifa fanfreundschaft circle across Europe.
Finally, though I don’t actively follow them, watching Boca Juniors live at La Bombonera is my ultimate bucket list item.
I don’t really have a ‘second team’ in England or Norway.