Are These doppelganger and ghosts?

I was out biking with my dad just like the old days, we traveled 2 hours aways from our house and then when we were tired we decided to head back, an hour later I see 2 people behind us they looked similar to Eddie And Gabbie, and j told my dad "hey look those are my favorite youtubers" he stopped looked behind and said "there's nobody there" I was confused as they passed by scared that I might have saw doppelgangers as ghost or doppleghosts.