How would I set up a dick appointment?

Hi. I’m doing this anonymously because I don’t want any back lash. I’m in high school and I don’t really know how to set something like this up with my boyfriend. My parents are not home that often because their lawyers but they recently started working privately so their home more. I don’t really know when his parents are home but I’ve never done this before and don’t want to risk getting caught. Any tips?