Bicycle detail

In this situation I was only trying to be helpful ad borrowed my bike to a perso and I was hoping that I'd be equally respected in regards to what I was hoping would become a good Samaritan type of offer as the person knew it was my only form of transportation and that I would need it back as soon as possible... Well I was an idiot and the bike was never returned... I think it wasn't appreciated and I hope I can get my trek back I have been without it for a long enough time for it to have been found its a smaller frame I'm 5 FT tall so its a smaller frame white all working parts... I am fuzzy on the serial# year and model, I knew I should have registered it ? At this point I'm just trying to get it back so I can let my legs have a break