If it is Saturday to Tuesday, plan for Legoland on Sunday and Monday so that you have a full day for each park. I assume you are Chinese and will take Grab everywhere.
https://cnalifestyle.channelnewsasia.com/travel/jb-medini-legoland-johor-bahru-379946
1. Puteri Harbour - some pubs and restaurants
2. old Gelang Patah- Tian Lai or Chua Kee for seafood
3. Eco Botanic - new mall
4. Sunway Bigbox - BookXcess
5. Mall of Medini - an open mall adjacent to Legoland has a nice supermarket and some food options like KFC, BK and Secret Recipe.
In my annual visits I have not come across visitors in just bikinis. I think it is unspoken- the ladies go in 1-piece swimsuits or they cover up their bikinis. There is not much in the way of food at Premium Outlet. I suggest to visit on the Saturday.