Sports isn’t something you just come to like, it’s something you actually grow into from time. It’s a good thing you don’t have a time to grow into it as, you can actually start liking a sport from a much later age but before that fully materializes, their have to be some level of interest towards this new thing you want to be involved with. You start by understanding how the game is played before getting to know some of its key players and you keep up with the sport, be a fan and be active at it.
You are also right that sports is not like something that one person just came here and he just liking it. There can be exceptional but most of the people for liking a sports or a team they have to first gain knowledge and understand the sports then they will choose the favourite team for him on depends on his favourite player or the performance etc.
If anyone notices, after watching our games for years, we select one favorite team and sometimes change them.