Don’t be surprised if things don’t turn out the way you plan. Indeed, often it seems like they rarely do! But Proverbs 16:9 explains why that is often the case: “The mind of man plans his way, but YHWH directs his steps.”
We can (and should!) plan. It is a good and godly thing to do, as some other Proverbs make clear. But we also need to remember that we are very limited in our vision and understanding. God sees more than we do, and He has a bigger plan than we generally understand. So although we may “plan” certain things, He can — and will! — interrupt OUR plans, with something He has ordained in His wise providence. These things may look to us like “distractions” or “interruptions” — and sometimes they are. But sometimes they are also the hand of God, directing our steps in His more perfect way.
C.S. Lewis wrote: “The great thing, if one can, is to stop regarding all the unpleasant things as interruptions of one’s ‘own,’ or ‘real’ life. The truth is of course that what one calls the interruptions are precisely one’s real life — the life God is sending one day by day.” So often the “interruption” or “change of plan” leads to the life we never expected — but exactly the one which God ordained for us.
So make your plans; it is not wrong to do so. Just don’t be surprised if somewhere along the way God changes them, and directs your steps in an unexpected, but better way!