Hi,

1. What's the difference between "quotes" and "quotation"?  

Consider "To be or not to be". The words are a quotation.The enclosing inverted commas are quotation marks, but this term is informally abbreviated to quotes.

2. What's the difference between "warn" and  "warn of" (verbs)? 'Warn' is the base verb. The common syntax is 'warn someone about/of something'

3. meander: wind or turn in its course.  What does 'wind' mean?? A road or river that winds typically goes in the shape of a series of 'esses'. We often say something 'winds back and forth'.

Turn in course means it changes the path it goes? Yes.

Best wishes, Clive