I went there recently, 5 days should be easily enough to cover all Hong Kong, Disney land if you visit on weekdays, one day should be enough to cover most of the rides but if you want to explore everything then two days is good. Other than that there’s Ocean Park and Lantau island, for shopping we just visited some local markets and a short city tour. Also if possible add a trip to Macau too, the Venetian hotel is worth a visit there.
In terms of budget similar to what others have mentioned, local food can cost you around 50 to 60 HKD per meal, Indian food little more expensive. Transport there is very good everything is connected through metro.
Yeah lol, had the same experience with the local taxis.