1999 Nissan Maxima Stop Light Car Would Into Gear Friend Andi Pushed Across

I was at a stop light and the car would not go into gear. So a friend andi pushed it across the steet, the cae suddenly went into gear. So while driving it i noticed that it was very diffucult yo put the car into any gear. When i exited the freeway and made a right turn the car will not shift into gear again, so i pushed it to park it. Went home to wsit for someone to come help me. And hour later when we returned to the car, it shifted into gear with no proble. What is wring with my car