You have to extract it first. You do that by clicking the file once, then the three dots on the top right of your file folder, and then pressing extract and accept. After it loads you double click the TADDS with the little lady icon next to it.
Some games don't name their little lady icon, and its instead called (something) 34, which is irrelevant to this game but needed knowledge if you want to download other games on itchi.io. Always click the little redhead lady. Though sometimes creators will put in their own custom picture for the game, but you should be able to recognize it anyway because it'll match the vibe of the game you're downloading.
Also Also, don't place the icon on your desktop. When you open it that way, it doesn't always work.
The control button lets you skip dialog btw, and escape will lead you to the save/load screen.
But if you mean how do you play an otome/visual nivel game: just click on the square options to unlock different dialog. Though first you click on your preferred uniform and put in the came the characters will call you. In Zoobles route, much like the uniforms, there are two chosen pictures you click on to choose as well. The dialog doesn't move like an audio book either, you right click or press spacebar. Although in other games the spacebar might get rif od the dialog to so you can see the full art until you press it again.