So you want to get started with internet of things projects? The SAM Labs Explore Kit can help. It is designed to get you started with electronics and coding. It comes with 3 fully-rechargeable wireless blocks (LED light, button, and buzzer). You can use these to build your own smart door bell or wireless buzz box.
The SAM Labs Explore Kit comes with an app that lets you program your smart projects visually. You can get the kit for under $105.