A faster shutte speed so camera shake doesn't soften the focus would make then sharper.
A longer focal length makes it easier to blur the background. Shorter focal lengths eventually begin to distort the subjects face.
Lightroom is not a good tool to use for converting to black and white.
A lot of new photographers get Lightroom not understanding that it's editing function is not it's main purpose.
Lightroom was developed by Adobe for professional photographers that make a lot of photographs, like more than 1000 a week, week-in, week-out. Lightroom is Digital Asset Management (DAM) (database) software that allows a more streamlined work flow for editing images in big bunches, and for quickly retrieving photos in various sepate folders that have common keywords. Like searching for all the photos that have the keywords Bride, blue, high heels, toast.
Lightroom was intended to be a compliment to Photoshop CS for photographers. It was never intended to be a sole image editing solution. However, many people buy it simply because it costs less than Photoshop CS.