18, sparse facial hair and no chest hair. Weird?

It's you. Many, maybe most, women prefer a naturally smooth, light-bearded man or a shaved-chest nowadays. Five percent of men never grow chest hair (paul newman had none), and these men almost never go bald either. Enjoy your body, develop what you've got, stay fit, love responsibly, and be aware that you'll be liked for who you are rather than your smoothness/hairiness.
Not weird at all. This is mostly genetic. It doesn't mean you have any less testosterone or anything like that. It's just good 'ole genes.