No, I'm not calling you an idiot or implying you are one. 'K?
Now then... the first installment of *The Idiot's Guide to Writing a Romance Novel... Part 1*.
The first thing you need in order to write a romance novel is an idea.
Yes, an idea-- about the story you want to tell. It's not a requirement for you to know how the story goes from start to finish, so don't let that hold you back. A story is a series of events that build upon the previous events, leading towards a climax (git yer minds outta the gutter) and a resolution. In romance, the resolution is the Happily Ever After/HEA
So, take your idea, even if it's just an inkling at the moment, and get started. It's as simple as that.
For the moment.
Stay tuned. There'll be more entries into my Idiot's Guide to Writing a Romance Novel.