being a Celtic fan is fine, i would bet it would be boring. Only broadcasts you'll see on TV is UCL and SPL games on FxS+. They will walk to the league title every year until Rangers get back up to the first division which will still be another year. I watch Rangers on streams and FxS+ when I can. There are a lot of great documentaries on youtube about their rivalry.
(i have watched all 4 of these, the first two are a great watch for any fans of rivalries of any kind)
I got a Spaces a Celtic champions scarf when I was over in Scotland and Glasgow this summer for his bday! and I have some Rangers gear as well, so like I said no shame in choosing a Scottish club.