If you want to become a good Data Scientist then you can learn on your own.
You can start learning from blogs and tutorials. I would like to suggest you this insightful Data Science tutorial.
Also, if you want to dive deep into the field of Data Science then you must watch this video tutorial on Data Science:
So, ultimately Data Science has a very bright future ahead and if you are a beginner who eagerly wants to become a Data Scientist then you must be a professional in Data Science and you need to have a certificate for proving it, so, you should go for Data Science online course to make your career rise to the next level.