@Mariafcurrea 

Start a flow with trigger Placed Order (Shopify Metric), than use trigger splits Item equals or contains product X, yes path would be for people who bought that product and on the no path you can add another trigger split for the next product in line.. and so on you can add as much products as you want in that flow and beneath the split you can create the specified emails that you want people to receive depending on which product they bought.