Does Earth have a flag and anthem?

UN..flag, yes. Anthem, no.

O Earth, O Earth!
I live my life on thee!
With nations and seas and a 40km girth,
High shall my praises be!

Maybe, if every conflict on Earth was resolved and everyone lived in peace, no war ever.

Flag of the United Nations (official)
Hymn of the United Nations (unofficial)

The United Nations is not the same as Earth, however, so the answer to your title question is “no.”

Why would their be an earth flag or anthem. AFAWK we are the only planet with life.(though I highly doubt this)

There SHOULD be an Earth flag, with or without an anthem. Maybe it would be the first teeny baby step towards people feeling like the whole planet it a community. It could eventually lead to bigger steps to help us be neighbors rather than enemies or anyway strangers.
I’m ashamed to think about an anthem though.

Earth we love you we really do,
Even though we use up your gifts,
And coat you in filth,
We remain ever loyal to our darling plaaaaaanet.

Found the Earth’s flag

Yes. Here it is: https://www.youtube.com/watch?v=jM6r-BIxETY

@ragingloli That sounds like it’s from a video game but I can’t but my finger on it.

@dxs
It is from Star Trek.
United Earth, founding member of the United Federation of Planets.

@ragingloli This is what I was thinking of. I remembered hearing it when Roy won a battle on Super Smash Bros.