(2) As you said, you can choose to wear thermal underwear inside and a sweater and coat with a high collar or round neck outside in winter. If you choose an old sweater, you can wear a cotton casual suit for a sweater with a round neck, but be careful not to have too bad quality, otherwise it will not be effective! Pants are preferably jeans, which are generally light in color and should be matched with your coat. You'd better have a pair of casual shoes in the same color as your coat or sweater. You can wear more famous brands if you can, because wearing famous brands can show your noble temperament!
(3) In fact, other people's suggestions can only be used as reference. How to wear it depends on your specific situation. I take a mature route and choose mostly brown, blue, black and brown. Of course, as my friend on the first floor said, don't wear more than three colors, or it will look messy!
(4) Be careful, the most important thing is cleanliness. Even if you are famous all over, if you are swollen, it is equivalent to not wearing it! !