I recommend English Grammar in Use 4th edition by Raymond Murphy. A paper copy is reasonably priced and there is a PDF floating around the net.
1 - I like winter (most common) or I like the winter (season). Unit 74. children (concept) / the children (specific children)
2 - fun/funny have different meanings. fun = enjoyable. funny = comical.
3 - We also enjoy going camping. Unit 53. Enjoy takes a gerund (camping). Enjoy to camp is incorrect.
4 - Do you like camping? Unit 58. Like takes a gerund (camping) or an infinitive (to camp).
More common is "Do you like to go camping?" or "Do you like going camping?"
Unit 53E. "to go camping/swimming/sailing"
5 - I almost always watch TV. Unit 110. Adverbs of frequency.
6 - My hair is black. My hair is jet black (like a crow or a raven or a stone called jet).