There are geographical regions in League kinda, they're just country/continent size. I enjoy watching the American teams try to compete with other regions (Europe, Korea, China etc.) People generally just root for their region to do well.

As far as rooting for teams within a region, it usually boils down to finding your favorite personalities like that other guy said. Most of them stream on twitch for hours every day.

Also, all of the local regular sports teams I grew up rooting for never win anything so having no ties and getting to be a bandwagon fan in eSports cathartic for me haha