JacDac
BBC micro:bit V2
KittenBlock
KittenCode
MakeCode Introduction and Tutorial
Meowbit
FutureBoard
Nanobit
Micro:bit Expansion Boards
KOI AI Camera
Wifibrick and IoT Solutions
Functional Modules
Actuators
Educational Kit Sets
中文版Sharing Hub
There are both free and paid IoT platforms, here are introductions to some platforms suitable for beginners.
ThingSpeak:
MakerCloud: