Hello aspirant

There are plethora of options if you want to gain knowledge through online. The following are the best sites for coding related stuff, Javatpoint, W3schools, ,Udemy, Github,Codeacademy,edX ,Tutorialspoint etc.

For learning basics in electronics, you can choose your preferred course from Coursera, udemy etc and can improve your knowledge. Some of these sites may charge money and some will provide with free of cost.

Hope this helps. Good luck

Hi aspirant!
hope you are doing good.
According to my preference the best site to learn c++,java And python are given below
1) Code Academy https://www.codecademy.com/learn/learn-python
2) W3 schools https://www.w3schools.com/
3) Code With Harry https://codewithharry.com/
4) The odin Project https://www.theodinproject.com/
5) Tutorialspoint https://www.tutorialspoint.com/
6) studytonight https://www.studytonight.com/
7) Geeks For Geeks https://www.geeksforgeeks.org/
8) Java TPoint https://www.javatpoint.com/
9) Sololearn https://www.sololearn.com/
10) TechdevGuide https://codewithharry.com/

Hope it helps !

Thanks!