Google search is definitely a best way to find study materials, problems solution, questions and answers, notes etc. Everything is on google. That’s why it is the best search engine in the world.
It is best for everyone to learn things at your finger tips. Google makes Self learning easy for us. Showing the best sites that provide us lot of information. This is my favorite place for learning things.
If you don’t like to read things instead of you like watching tutorials and understanding the things. Youtube is best for anything related to videos. It is a great platform. No one is better than this when it comes to ease and free tutorials.
Unacademy is also a good platform for learning maths, GK, and things related to government jobs of india. Cracking government job, SSC, UPSC, IBPS, and more.
One of the best platforms for learning and improving skills. Lots of high quality tutorials. You have to buy the course for watching complete tutorial videos. But it is worth to buy that. Really awesome content and quality.
Another great and popular hub for learning different subjects. You can check this also. There are many websites where you can self study online and learn many things. Some more sites that you may like coursera, udacity, codeacademy, tutorialspoint, w3schools, wikipedia, collins connect, lynda.com, skillshare, slideshare, geeksforgeeks etc.