Micro:bit is a smaller and more compact board for starters. It has fancy built-in features such as LED display, buttons, and gesture support so you can build simple projects without the need for external components. It can be programmed via Javascript or Python.
Arduino is more geek style. It has a lot of pins for connecting to external devices but built in features are lacking. No built in display and no built in buttons but a lot of pins. In other words, it relies heavily on the use of external devices. It does support a lot. And you program your Arduino board using C++.
MakeCode is a simulation environment for Microbit and nothing else. It allows you to write Javascript or Python code. In terms of hardware simulation, the support is not as extensive as that of the Tinkercad.
The Tinkercad platform supports Arduino, Microbit and other circuit types. It has very extensive support for different electronic components. For Arduino you can write C++ code on it. For Microbit you can write Python code but not Javascript.