how to stop complaining so much

I feel like a horrible friend because my friend is upset that I complain so much, I dont realise it sometimes though because I dont think I know how to converse properly? I dont know how to help it or learn to stop it. I have caught myself and stopped complaining and started to make myself like things and say good things about stuff, but I still complain too much.

Like for example (pls dont lynch me, this is just an example😭) like if a new fortnite collab comes out that I dont particularly like or i have a problem with it, ill talk trash about it, or if im talking about something like DC and mention how I dont like modern Harley Quinn.

Its stupid, but i feel like i need to do more to stop myself from complaining.