What should my book be about

If आप want your book to be similar to the ones आप mentioned it would be और within the action या adventure genres. All good stories have romances in them. Not all, but a lot. I think आप should write whatever आप feel led closest too and see where it takes you. Who knows, maybe you'll start on a dramatic and action packed romance and it might lead आप into the characters becoming vampires. And that might only set off the path of starting a series या trilogy. It all depends on what आप feel आप should write. It is your story and your imagination. Let it run free!
I hope I could be of some help. Good luck with your book!!!