This is excellent advice. Laying out an entire world and populating everything isoften pointless. The players will go off on a tangent or whimsically shatter your carefully planned encounters. Plan for what theyre likely to run into soon, and worry about the rest later. As DMjust roll with it
In subreddit r/DnD
In a post titled:
Which do yall prefer DMing or being a player? Personally I love DMing much more than playing as a character as I love the story building and progression you can be in control of.