Here is information to look over including advanced topics. There is a lot of information on the web that is very useful, but there is also a lot of complicated physics that you do not have to understand to get your projects working.
Want your own starter Arduino Kits?
If your feel TinkerCad Circuits is not enough for you, you can get your own starter Arduino Kits and other hardware on the following websites: Adafruit, Sparkfun, and Tinkersphere.

Instructables
Instructables is a community for people who like to make things. Our community shares what they make in a step-by-step format that we call an Instructable.
https://www.instructables.com/circuits/
Light Sensor Explanation
https://www.elprocus.com/light-sensor-circuit-with-applications/
Capacitors
Transistors
http://www.explainthatstuff.com/howtransistorswork.html
LEDs
https://en.wikipedia.org/wiki/LED_circuit
How to Read Resistor Values
http://www.orcadxcc.org/resistor_color_codes.html
Schematic Symbols
https://learn.sparkfun.com/tutorials/how-to-read-a-schematic
Electric Circuit Lessons
https://www.allaboutcircuits.com/textbook/
More Example Projects
https://www.tinkercad.com/things?type=circuits&view_mode=default
Introduction |
Lesson One: System Design |
Lesson Two: Basic Circuitry Knowledge |
Lesson Three: Electronics Tools |
Lesson Four: Lighting an LED |
Lesson Five: Tilt Switch |
Lesson Six: Photoresistor and LED |
Lesson Seven: Button with Piezo Speaker |
Lesson Eight: Dimming an LED |
Lesson Nine: Button Input for LED |
Lesson Ten: Ultrasonic Sensor Alarm |
Further Resources |