experienced frontend UI / UX WordPress designer to improve "look and feel" of a responsive design WordPress child theme

Hello, I’m looking for an experienced frontend UI / UX WordPress designer to mainly improve "look and feel" of below responsive design wordPress child theme to look similar to some of webpages in [login to view URL], while keeping it lightweight and responsive for mobile web. For example, I want to edit the attached image to look almost similar to [login to view URL]'s homepage. In addition, there will also be low-medium level frontend and backend WP configuration and WP development. Child theme: [login to view URL] Overall: 1) I'm looking to edit 10-12 webpages to look more modern (UI, UX, colors, fonts, images and etc). More importantly, to look similar to some of webpages in [login to view URL], while keeping it lightweight and responsive for mobile web. 2) Exclusion: I don't have a mobile app, so disregard all instances requires downloading a mobile app in [login to view URL] a. Example, in my theme, there is functionally to upload a photo and provide all necessary description (similar to craigslist). 3) Note: there might be low-medium level frontend and backend development required. a. Before granting access to the homepage, the site must ask the NEW and anonymous user if he or she is 21+ (similar to [login to view URL]) . If the user has said yes before, do not make this popup reappear b. When on the homepage and when there are multiple classifieds displayed, they must include the number of “likes” and “comments” c. I want all buyers and sellers have the option to sign up or login using FB, instagram, , twitter, and other social media (default is email). d. Allow users to insert hashtags into their description when they post a classified. In addition, allow those hashtags to be searchable. e. After posting their classified, the user can optional share it within their into social media account. If they post, they can optional to a cancel before posting f. Anybody can access and subscribe to the blog section to post their own or comment. In addition, these blog posting will be content within the email newsletter that are distributed to users and within social media g. Optional for buyers and sellers to “like”, “offer”, “watch”, and/or “comment” on each classified posting h. Buyer and Seller can chat about a classified posting i. Be able send web notifications (chrome) to buyers and sellers. About you: • You must have prior UI and UX experience that's targeted for millennials in the USA! • Since this is a wordpress child theme, do you have experience using Firebug? See link: [login to view URL] Please let me know if you have how much it will cost and how long it will take. You can provide BEFORE and AFTER examples.