78% of retail investor accounts lose money when trading CFD with this provider. You should consider whether you can afford to take the high risk of losing your money.
When trading the actual underlying security, spot instruments can be physically delivered immediately "on the spot". As for futures, you pay a predefined price to have a good delivered to you at a predefined date in the future, let's say one year.
Since the goods won't be purchased immediately, there is a cost associated with carrying them, including insurance, interest, and other related expenses, until they are delivered to you.