It's awkward when people start their sentences with "I just want to say..." well there's nothing stopping you. You could just say it instead of telling us about how it's what you'd like to say, amirite?

If people got rid of every little minor annoyance in the English language, there would be no English language.

I just want to say....uhh.....damn I forgot...

That or "can I just say that..." Its like, sure but you are already saying it now.

There's a girl in my class who says that before every single thing she says. She goes, "Well, um, I just wanted to say that..."