Adam Smith launched the modern science of economics, but there are many books containing the advances since Smith wrote. Starting the study of economics with Wealth of Nations would be like learning physics starting with Newton’s Principia Mathematica (Mathematical Principles of Natural Philosophy). Neither are up-to-date and both contain many errors.

Once one is well-versed in Economics, at least through Samuelson, Smith’s work is valuable if you are interested in the history of economic thinking or want to discover what all the fuss is about. Smith’s work was monumental because of what it started but is wrong in many areas - much has been learned in the last 240 years. I read and enjoyed Wealth, but I had taken 8 university economics courses and read thousands of pages before tackling it. Some of Smith’s discussions (the role of capital, for example) are timeless and have not been improved upon.