Data science is hard because of the experience and knowledge requirements for junior developers/engineers. Another factor is the tech maturity and development. Data science is a field highly dependent on technologies such as databases, cloud computing, analytical tools, and programming among many and these areas are presently undergoing disruption and rapid change. This can make it difficult to establish credible expertise since performing a data science role can be hampered if the tech stack is unfamiliar to the individual. If you want a detailed explanation of Data Science then do check out Data Science Tutorial which will help you in understanding Data Science.
You can get a hands-on project by referring to this Data Science Certification which will teach you Data Science from scratch to advance.
And if you are more into videos then do check out the following video tutorial which will help you in mastering in the field of Data Science: