For a rationally and mathematically inclined mind, data science is not 'tough' to learn, but it is time taking for sure. The areas that a data scientist needs to cover is vast, and each area has its tricks. It is time-consuming to even become reasonably proficient in all or most of the areas. For example, a statistician or science expert knows the math but might lack experience in data scraping from the web and storing them in a well-defined manner. If you want a detailed explanation of Data Science then do check out Intellipaat’s Data Science Tutorial which will help you in understanding DS.
You can get a hands-on project by referring to Data Scientist 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: