Why can l not open the door what is the problem what can l do short and long term

If the key wo not even open the door, then it sounds like a linkage has come undone from the locking mechanism. The only way to fix that is to take off the door panel and see what parts are broken. A real fun job..not!
Short term fix.do not lock that door. If you have to lock it, then start getting in from the passenger side.

Need more info, & can not write back & forth so l will just go down the list.
1) Key turns but dose not unlock door. This means that the rod that goes to the back of the lock has came off. This also means that is the reason door is not unlocking with the remote as it pops the lock rod inside the door which pushes the lock open.
2) Key does not turn lock at all but works passengers side door. This means that the locks has been changed in the door, but that does not sound like the problem as u say the remote does not open the drivers side door so more than likely the rod has came off the back of the lock.
How to fix it? Well not an easy job as l use to be a locksmith, cutting keys for doors & egnitions if that is the way u spell it. Have to have small hands & arms. If u do want to know just drop me a line & l will try & explain it to you.
Hope this helps, have a Blessed Day, slowboy.