よ is classified as a 終助詞（しゅうじょし） (sentence ending particle) in Japanese. In most cases, it is used to convey new information to the listener, or just to add a bit of emphasis. Like most sentence ending particles, it is simply added to the end of almost any sentence.
Despite the regular use of
よ being to convey new information, it is very regularly paired with
ね, to convey the meaning of ‘right?!’. Literally it means something closer to ‘I think (A), and I bet you think (A) too!’.
Did you notice that there is a だ after the noun, but not the い-Adjective? This is not a unique rule for よ, but just one of the regular conjugation rules introduced in the lessons for い-Adjectives and な-Adjectives. It is also acceptable to use ですよ after either type of adjective (or noun).