I saw some of the recipes do not require baking soda...why is that?

they just call for baking powder - some call for baking soda - depends on the recipe

what difference would it make if one is present or both is present or none is present? (i'm really sorry for being a noob)

It is best to follow the recipe as written. Alone - baking soda is bitter and does not fluff so you would need to add vinegar or lemon juice because baking soda needs acid to counteract the bitterness and make it fluff. If you have cream of tartar, you can make your own baking powder.

If a recipe calls for baking soda - you cannot use baking powder - and if a recipe calls for baking powder you can use baking soda but you will need to add more and it can effect the taste.

With many recipes you are better off just leaving it alone and following the recipe the way it was wrtten.

Great! Thanks I get it now Mama! Sorry if I ask too many questions though. But it's simpler than reading stuffs from books. Thanks again!