Also I have a doubt that is it a good option to learn from platforms like this or I should go for somesql server online training . I have searched for the solution of my queries in various above platforms which helped me up to some extent only as it was not directly given by any expert or trainer.
Some websites provides structured learning materials, peer or teacher interaction, and SQL Server courses. But if you're looking for more individualized coaching and practical instruction, have a look at Iqra Technology's SQL Server online training courses, which are taught by qualified professors or business specialists. Choose according to your budget, personal goals, and learning style.
Numerous websites offer complimentary online courses, providing learners with access to a diverse array of educational content at no cost.
If your goal is a certification of some kind, then those examples seem reasonable. If you're not, there are many other resouces that'll help you ramp up on the technology. w3schools is just one example: SQL Tutorial (w3schools.com)