When did sun and planets form?

From my own knowledge, planets existed since Earth was created in the Big Bang, so, from what I can see, it means that the planets existed in their basest form about 13.7 billion years ago. However, Earth has, theoretically, only been earth for about 4.54 Billion years, so somewhere nearer to 13.7 bya rather than 4.54 bya.

I'd say 13.7 billion years ago.

Earth was created after the big bang

-- planets formed almost instantly

no sciences have found the exact time