Hi Pao_lila.
1,2. you can change color by go to Theme Option > Color Scheme > Header Color > Menu and you change change size in Theme Option > Typography > Body Font > Font Size
3. Please go to Theme Option > Color Scheme > Footer > Footer background
4. you can find icon and class of icon at https://fontawesome.com/v4.7.0/cheatsheet/
5. Please go to Theme Option > WooCommerce > Product Detail Settings > Remove Size Guide image and Shipping & Delivery Content
6,7. You can change label by use plugin Loco Translate and when create new language choose English-US
http://support.janstudio.net/forums/topic/theme-translation/
I’m sorry it can’t show label of price Regular Price/ Sale Price
Kind regards
Harry
Premium Wordpress themes and plugins, Best WooCommerce theme https://themeforest.net/user/janstudio/portfolio?ref=janstudio