D&D for two?

Hey guys, I have a question for you all. I am a new DM that has been playing with a regular group, including my boyfriend, for a couple months. Well, everyone cancelled on us, for the third week in a row and my boyfriend, who is incredibly enthusiastic about it, has been really looking forward to it and is bummed that we got cancelled on again. I wanted to surprise him with some kind of Dungeons and Dragons for two, or something similar. It would be really awesome if you guys could give me some ideas, because I have no idea if there are any two-player formats!

Sorry if I sound incredibly uninformed, I was only introduced to D&D this past year!