Sorry, this might be a stupid question ....

My game "The Ruins of Calaworm" is now out for about 3 weeks, and I was wondering how sales work? This is the first time I've ever released a product that peeps gotta pay for, so please bear with me. <3 Are there site-wide events which I can join, to put my game on sale, like "Halloween Sale", or sth. like that? Or can I just choose to put my game on sale whenever and for however long I want?

Thanks!