Nostr can be a bit frustrating. There are not really any groups / channels implemented. And relays tend to be very general- not topic specific either.
The best I've found is to follow people that that are posting interesting content. Finding them can be a bit challenging.
I find new folks to follow when I see them on a post / comment / mention from someone I already follow. That works, but is somewhat slower way to grow the network.
I also search for hashtags of interest. #grownostr is a great one to use for a wider variety of posts, but you can try #business #woodworking and see what you get.
From time to time, I also scroll through the 'global' feed for topics and hash tags of interest.
Hope this helps you find more posts of interest to you!!!