https://codepen.io/flamingkrypto/pen/LdWvpX

https://codepen.io/flamingkrypto/pen/LdWvpX
0
#1

How would I have changed the header color I tried what I knew and nothing worked?

#2 
h1 {
  color: hotpink;
}

Also float:center isn’t a thing, height:auto isn’t needed in this case, and you need a closing curly bracket on your CSS declarations.