Getting into physical bookstores depends on where you publish through. If you want to get into physical bookstores, you need to publish through IngramSpark, you need to have returns on, and you need to offer 53-55% wholesale/retail discount. Self-published authors usually do not focus on physical bookstores as a major revenue stream, due in part to the difficulties associated with it. But it is possible. Check out this blog post for more information. It needs to be a targeted and intentional strategy, not just something you do hoping it happens.