Questions I Don't Know How To Ask Or Deal With In A Relationship

So I'm 4 months into a relationship with my boyfriend. This is my first serious relationship and I'm 25.
  1. How do I ask him about kids or the future without freaking him out? Is it too soon?
  2. Do I wait for him to say I love you? When is the right time?
  3. Do I let him stay over at my place (I live with my parents)?