Most definitely a common noun.
Yes, wheat bread is a common noun; a singular, common, concrete, open compound noun.
The noun bread is a common, concrete noun, a word for a thing.The noun bread is a mass (uncountable) noun, a word for a substance; for example: We can have some bread with dinner.The plural form, breads is a word for 'types of' or 'kinds of' bread; for example: The breads we have are rye and Italian.
Yes, wheat bread is a common noun; a singular, common, concrete, open compound noun.
The word 'bakes' is not a noun; the word 'bakes' is the present tense for the verb 'to bake' (bakes, baking, baked). The noun form 'bake', as in clam bake, is a common noun. Noun forms for the verb 'to bake' are 'baker', one who bakes, a common noun; and the verbal noun (gerund), 'baking', also a common noun.
Some collective nouns for loaves are a batch of loaves or a stack of loaves. Other collective nouns for loaves would be a word suitable for the context of the loaves; for example a basket of loaves, a shelf of loaves, a case of loaves, etc.
The noun 'toaster' is a singular, common, concrete noun, a word for a device for browning slices of bread; a word for a thing.
The plural of bread may be bread or breads. Usually, one refers to many loaves of bread, or many different types of bread, but the word breads is not unknown.
The word 'loafs' is not a noun. The word 'loafs' is the third person, singular, present of the verb to loaf (to spend time idly).Example: After finishing a chore, dad loafs on the patio sipping a beer.The noun 'loaf' is a singular common noun. The plural common noun is loaves.Example: While dad loafs on the patio, mom is baking two loaves of bread in the oven.
The pronouns that takes the place of the noun 'bread' are it, its, itself.The noun 'bread' is an uncountable noun, a word for a substance, so there is not plural pronoun for the noun 'bread'.
The noun 'toaster' is a singular, common, concrete noun; a word for a type of appliance; a word for a thing.
The word banana is a noun, a common noun. When used as an adjective, as in banana bread, it is not capitalized. Any common noun can become a proper noun if it is used for the name of someone or something, such as the movie 'Bananas' (1971) or Banana Republic brand.
Since bread is a "thing", it is a noun.