Kind of a funny story. Never asked a girl out before, as I'm extremely shy, but still quite sociable with people I know. Then in 2016 I get my first job on a MediaMarkt and meet like a hundred people all of a sudden. So we form a group of like 5 people, one of them being a really, REALLY funny girl that loved the same games, music, movies, etc. as I did.
So we essentially became best friends, and we start finding out not only that we lived like 5 minutes from each other, but also that we had gone to the same places and events, at the same time, without knowing each other. With both of us being as shy as we are, it took until some friends of us told me "dude, you spend all day with her, and she actually told me that she likes you". Got the courage to ask her out and she agreed. All of that happened in the span of like, two to three weeks. We've been together for two years now and it's definetely been the happiest time of my life.
OP, I'd say suggestions like Tinder and OKCupid are probably ok, but as you'll see on most responses to this thread, it'll just happen naturally.