A noun is, essentially, a thing. Any person, animal, object, substance, abstract concept, fictional character – anything in the universe which is capable of carrying out a verb. ‘The universe’ is also a noun. Here is a list of examples of nouns:
Cloud
Beer
Chicken
Marmite
Segway
Teacup
Nostril
Poncho
If the noun is a group of more than one thing, it’s called a plural (i.e. Beans, tubes, cartographers). Singular nouns which describe a group of multiple things (i.e. the government, the police, the flock) are called collective nouns.
In German, every noun has a gender. That literally means that it is classified as either male, female or sexless – although grammarians prefer the terms masculine, feminine and neuter. To explain why this is would take me several thousand words and a couple of Master’s degrees, so I’ll just have to ask you to accept that that’s the way it is. It’s really important to learn a word’s gender at the same time you learn the word every single time, as gender mistakes are one of the most common and most obvious mistakes German learners make – and you don’t want to embarrass yourself when you’re chatting up some fitbo called Franz at a cool hipster bar in Berlin.