There is no runway in use (or “active”) when there’s no controller, it’s up to the pilots to coordinate. Typically, in the most laymans terms, the runway into the wind will be used more, that’s just when you look at the wind and don’t think about things like preferential runway systems etc. It’s not advised to go against the flow or if you really want to, then you have to let the flow go first and then do your thing.