Hi, if you only want to do this in the same game session use a global bool variable.
If you want to do this also for the next game sessions,
Use playerprefs bool or easy save bool.
At the start set a bool test (false) and on the first time after bool test,
Show the object and then set bool to true.
Next time (reload) it should do the bool test again and it should test as true.
Now you can disable the object.