I enjoy playing Stellaris, I have the base game and have slowly been learning how to while not win … not loose horribly.
There is mountains of DLC and most of it is on sale. Is there anything people particularly recommend?
My focus has always been evolving through the tech tree and trying to build good enough defenses to hold the enemy at bay (learning you could customise ships was a game changer for me).
I think Utopia is the one that is most commonly recommended as a good first DLC, adding ascension perks and megastructures. I am not sure if they are still locked behind the DLC or part of the base game though, it’s been years and I think they were making changes to it.
You could also try asking in @paradoxgames, help them a bit with activity there
Utopia changes the most in the game in my opinion.
Utopia is a must-have.
Leviathan and Distant Stars are good for their prices.
Beyond that, get what sounds interesting. If you want to play as robots, get Synthetic Dawn. If you want planet-destroying weapons, get Apocalypse. If you like playing diplomatically, get Federations.