I am trying to login but it tell me that the password is not ok.
If you go in "Settings / Reading" .. simply check the "Your Latest Posts" in the "Front page display" .. that will make your blog articles appear on your front page, the rest is super easy you just need to create normal post with featured images.. for the slider, simply activate it in "Appearance / Customize" and give you featured post a tag of "featured". That's pretty much all there is to it.
Let me know if you have more questions.
here are the new logins :
Username : admin
Password : iy^6EOqHe!ZWU1Ieu3oNayAo
You can check the demo now, I've added some posts and activated the slider.
There seem to be some "caching" so make sure you refresh holding "ctrl + F5" and do it a couple time to make sure you have a hard refresh.
Let me know if everything is ok and let me know if there's anything else I can do for you.