What I mean is for example, is it allowed to marry your own brother, sister, cousin,etc? Is there a verse that says it is not allowed?
'laying bare the nakedness' is a hebrew expression for sexual relations. 'laying with' is also an expression referring to sexual relations. The laws in leviticus below are speaking about not 'laying with' or 'laying bare the nakedness' of any of the following close family members:
Leviticus 18:6 “‘YOU people must not come near, any man of YOU, to any close fleshly relative of his to lay bare nakedness. I am Jehovah.
7 The nakedness of your father and the nakedness of your mother you must not lay bare. She is your mother. You must not lay bare her nakedness.
8 “‘The nakedness of your father’s wife you must not lay bare. It is your father’s nakedness.
9 “‘As for the nakedness of your sister, the daughter of your father or the daughter of your mother, whether born in the same household or born outside it, you must not lay bare their nakedness.
10 “‘As for the nakedness of the daughter of your son or the daughter of your daughter, you must not lay bare their nakedness, because they are your nakedness.
11 “‘As for the nakedness of the daughter of your father’s wife, the offspring of your father, she being your sister, you must not lay bare her nakedness.
12 “‘The nakedness of your father’s sister you must not lay bare. She is the blood relation of your father.
13 “‘The nakedness of your mother’s sister you must not lay bare, because she is a blood relation of your mother.
14 “‘The nakedness of your father’s brother you must not lay bare. You must not come near his wife. She is your aunt.
15 “‘The nakedness of your daughter-in-law you must not lay bare. She is your son’s wife. You must not lay her nakedness bare.
16 “‘The nakedness of your brother’s wife you must not lay bare. It is your brother’s nakedness.
17 “‘The nakedness of a woman and her daughter you must not lay bare. The daughter of her son and the daughter of her daughter you must not take in order to lay her nakedness bare. They are cases of blood relationship. It is loose conduct.