I tried to change my door and when I closed the door to see if it shut right the door locked but just that door. Now car won't even start and when I go to turn the key it just beeps . Someone please help me ☹️

 

Your car thinks you're a thief so it's disable the car. You need to plug in all connectors on the door to there corresponding mates and turn off the alarm system.

 

There's a couple different things to try:

Try putting the key in the door, turning it to unlock position, and holding it for several seconds. This may get the car to realize you're not trying to steal it.

or...

If you put the key in the ignition and turn them to position 2 (car on, engine off) and leave the key like that for 10-15 minutes, the car should realize you have the key and bypass the alarm.

If you haven't checked for lose contentions yet I'd do that first!

Are there any anti-theft lights on the dash?