Why is my automatic transmission so hard to get into gear?

I have an 01 frontier that doesn’t like to go into gear. I will go into park just fine but when you want to put it in drive it will reverse or go into neutral. i have to put the shifter back in park and push forward then drop it into reverse then place it back into park before putting it in gear in HOPES that it will then go into drive. Additionally when sitting at a red light it acts as though it wants to take off even if the brake is mashed to the floor.