Most NOSTR clients fill your feed based on who you follow, and who they follow, etc.
So, find folks who have content you like and follow them. I am into #bitcoin, #skiing, #libertarian / #freedom, helping folks ditch #bigtech to run their own servers (self sovereign computing). Take a look at my posts, and if you are interested, follow me :)
You can also search for hashtags on subjects you are interested in to help you find others to follow too.
Post things of interest to you - hopefully more than just bitcoin and folks who like that will follow you!!!
Together we will #grownostr