It depends a lot which server you join, https://beehaw.org it's very welcoming, https://lemmygrad.ml is full of tankies that hate the West (supposedly it's about communism, because original creator is a communist, but it's more pro Russia pro China, anti US and in support anything the West doesn't support and vice versa). If you go to https://lemmy.world (the biggest server) you'll see mostly memes.

Though you can subscribe to different communities and customize your experience, often what you can experience from specific community depends on which server it is located.

https://programming.dev/ and https://lemmy.dbzer0.com/ might be good for technology related communities.