If you want run a ecommerce website then you need products to sale. So you have to create products in your site. In magento, you can manage products very easily. Now follow the steps how to create magento product from admin panel:
1. Login to admin panel then click on Manage Products under Catalog menu.
2. Now click on Add Product then you have to choose Attribute Set and Product Type then click Continue. (See below image)
3. Fill up the required field in General Tab on the left side(e.g. Name, Description, Short Description, SKU, Weight, Status, URL Key, Visibility, Country of Manufacture). (See below image)
4. Then Click on Prices tab on the left side and fill the fields(e.g. Price, Special Price, Tax Class etc).(See below image)
5. Click on the Meta Information tab on the left side and fill the details(See below image).
6. Click on the Images tab now browse the image then click on upload files button then check the radio button as shown in the image below.
7. Click on the Inventory tab then fill the required fields(e.g. Qty, Stock Availability) (See below image).
8. Click on the Cateogories tab. Now select the categories you want(See below image).
Now you can see the product you created in the categories you selected as point 8(See below image).