What Klaus said;
No one in this forum was born with electronics knowledge. Whatever we know, it is because we followed a four step process:
1-research and read many circuit descriptions.
2-build the circuit (and perhaps write the code) on your own. Best approach is a breadboard.
3-test circuit, and most likely, fail.
4-analyze and probe around the different circuit nodes.
Repeat steps 1 thru 4 until success is achieved.
Alternately, if one does not have the time or money to achieve the previous steps, an alternative which I have used several times, is to purchase a kit available on the web and build it.
Once that you got it running correctly, study the schematic, probe the circuit with a DMM or scope, and then perform some modifications and re-test.