When a card says, "It keeps all supertypes but loses all other types and creature types" like in !Reprobation , now supertypes are the first 2 texts that are before the hyphen and the subtypes are the ones after the hyphen in a card from what I know, but what are creature types? is it when Legendary Creature is written in the typeline of a card the creature type is legendary? or is it like Planeswalker, Artifact ... etc, or is it something else?
No. I am guessing you were the person on the Judge IRC channel (you could have just asked for clarification there). Supertypes are the words: Legendary, Snow, Basic, World, and Ongoing. These always occur before the Hyphen and always before Card Types.
Planeswalker, Creature, Artifact, Enchantment, Land, and Tribal are the card types a permanent can have (Instant and Sorcery are the other two card types). Creature types, Planeswalker types, Enchantment types, Artifact types, Land Types, Instant Types, and Sorcery Types are the words *after* the hyphen that correspond to the appropriate card type. So, Gingerbrute is an Artifact and a Creature (these are both card types). Food is the Artifact subtype and corresponds to the "Artifact" card type. Golem is the Creature subtype and corresponds to the "Creature" card type. So, if you put Reporobation on a Gingerbrute, it will no longer be an Artifact because Reprobation removes it. Which means it will no longer be a Food. It also won't be a Golem because Reprobation removes that too. It is *only* a Creature - Coward with a P/T of 0/1.
Let's take Thassa, God of the Sea. This is a Legendary Enchantment Creature - God. Legendary is the supertype, Creature and Enchantment are the Card types, and God is the creature subtype (it does not have an Enchantment subtype). If you put Reprobation on it while she is a creature she will still be Legendary, but will not be an Enchantment or a God. So, her type line will be Legendary Creature - Coward and her P/T will be 0/1.
Planeswalker, Creature, Artifact, Enchantment, Land, and Tribal are the card types a permanent can have (Instant and Sorcery are the other two card types). Creature types, Planeswalker types, Enchantment types, Artifact types, Land Types, Instant Types, and Sorcery Types are the words *after* the hyphen that correspond to the appropriate card type. So, Gingerbrute is an Artifact and a Creature (these are both card types). Food is the Artifact subtype and corresponds to the "Artifact" card type. Golem is the Creature subtype and corresponds to the "Creature" card type. So, if you put Reporobation on a Gingerbrute, it will no longer be an Artifact because Reprobation removes it. Which means it will no longer be a Food. It also won't be a Golem because Reprobation removes that too. It is *only* a Creature - Coward with a P/T of 0/1.
Let's take Thassa, God of the Sea. This is a Legendary Enchantment Creature - God. Legendary is the supertype, Creature and Enchantment are the Card types, and God is the creature subtype (it does not have an Enchantment subtype). If you put Reprobation on it while she is a creature she will still be Legendary, but will not be an Enchantment or a God. So, her type line will be Legendary Creature - Coward and her P/T will be 0/1.