The hook - Your first line should hook the reader. It should reel the reader in and make them want to know more. Look at your work in progress. Does your first line make you want to read on?
Do some research. Look at favorite books in your genre, do the first lines make you want to keep reading? Go to the library and pull books off the shelf. Which ones would you like to read?
Read the first line of Charlotte's Web. Fiction by E.B. White
First line: "Where's Papa going with that ax?"
Read the first line of A Horse of Course. Fiction by Shari Lyle-Soffe
First line: The very best gift at Aaron's birthday party wore a big red bow and a tag that said: 'Happy Birthday from Grandpa Roy'.
Read the first line of Earthquake. Non fiction by Susan J. Berger
First line: I hate to tell you this, but you can't dig to China.
Do their first lines intrigue you?