Andy Genius Hour Project(grade 8)

How to write HTML or more... make a background picture like this... so... gather up kidos'!! the brackets are the replacements of the triangle brackets the command input is (style) then (/style) in the middle you can put body {
background-image: url(https://BLAHBLAHBLAH.JPG)

this is the homepage of Andy Zhao plz follow ^(*<>*)^