I have created an online store and there are already some products added as the demo and I've also added some products but these are not showing on the homepage of my website. They do appear when I search them on search bar but my main page of the website doesn't show any products you can also check www.tedifier.com I don't have a lot of knowledge about Magento so please answer in simple words
I think you have used any third party theme. You have to first check in category pages where your new products show there or not. If not show on category pages then you have to try re-indexing using
System> Index Management.
The second possibility, there is some functionality given by theme to show the product on the homepage(e.g. widget) so you have to look into
System> Configuration > Theme Settings.