The most those at home courses can teach is theory and perhaps how to read the code book. They are at best a aid for on the job training.
The only way to become an electrician is to work for an electrical contractor and get training thru a good course. There are some good instructional material you can buy, but you will need an instructor or mentor to help you and explain the many ins and outs and changes to this trade.
There is no short cut.