Welcome Frank! Come on in. I think you'll find yourself in good company here with interests overlapping others'.
In terms of growing your feed, a common recommendation is following people who (1) tend to show up in tags you're interested and/or (2) write in compelling manners - of course, so long as they are things that you're open to reading/receiving.
For example: We've also got a few people here interested in photography as well, iirc. One place that happens to show up in is #tripreports, for the adventurous of us... that, or I'm just easily impressed by some of the shots people take in #tripreports. From there, you can dabble in who/what you're interested in following. In general, though, every Wednesday (on US time, I think that's today for you, though) we have a post called #pubski where people pop in and chat about whatever they want as if it's a pub. That's were I'd recommend getting a good feel for those that are in the site poppin' into the site. Of course, that's just a sample of who's available that week.
There are some tags out there that give you some insight to a handful of users around here like #adayinthelife and #3questions. Take your time with them if you go down those rabbit holes. There's a bit there.
On the flipside, another feature of Hubski is self-moderation, so you're free to mute/hush/block whoever you want or even whole tags. As such you can follow a person, yet mute a tag they post in that you're not fond of and vice-versa. Or just straight up block, that's cool too and none will be the wiser.
Probably missing more of the general spiel than usual, hope that's helpful, though. Welcome!
EDIT: I remember now. Hubski is still relatively small, so this is the "be the change you wanna see" bit in terms of "bring the discussion you want to see." You should be able to post now too, so you're all set if you have questions or want to post something you're interested in. Lurking for a bit is always an option as well. Still a quasi-lurker myself after a couple years.