If you look at the back of an iron, and there is a cut out - thats a cavity backed iron. These are easier to hit, different brands and models are suited to higher and lower handicaps. But these are generally easier to hit than blades.
If when you look at the back of a club, it is solid on the reverse then that is a blade, less forgiveness and harder to hit - these are generally aimed at the lower handicapper, however, there are always exceptions to the rule.
Blades are a long way off if you are just starting. No one says you have to move to blades, its personal choice. Scratch players can play with cavity backs, loads do.
Forget blades for now, go try some good starter cavity backs and see how you get on
Best of luck.