How do I keep my legs warm in the winter? (multiple questions)?

I just wear my normal everyday underwear but instead of leggings I would wear thermal tights. These can be worn with a skirt or under your trousers. Leggings might make you look a bit heavier and can restrict how much you ate able to move. If you wear thermal tights you can then put socks on top or underneath your tights. Hope this helps :)