The Splash page is where you can showcase your store logo. Tell about your store and any other relevant information. The rules need to be on the terms page. You can choose to have no splash page. You can customize one or use an externally hosted page. You will need a site with an SSL security certificate since it won’t work without one. It is easiest to customize your own or not to have one.
Lower on the page you can see your splash page. You can have more than one and switch them out if needed. If you click on the one that you have you can edit it.
Here you can edit the splash page. This is mine when I used the custom one. You can do a lot with it. The whole thing is just an image I made with a graphic program. I would add store updates at the top of the page when needed.