I am a Capricorn female, there is a guy I like I want to know if I am wasting time on him

Hi I am not friends with this boy but he is close friends with my sister and I want to know if he is gonna be the right man for me and if I am gonna spend my life with him in the future. My birthday is on December 27 1996 and his birthday is on September 15 1992. His name is Joseph. I just don’t want to waste my time if he isn't the right one. Your reply means a lot to me. Our zodiac signs are both compatible.