Hello,
i need to replace my front left door, and am wondering if a door from a sedan will fit into my Hatchback?

 

The front doors should be the same.
Make sure everything works in the current door correctly before you remove it(or write down what doesnt work), then if anything doesnt work when the new door you know if it was a existing problem or not.
I would recommended to get the same year/trim that way all the wiring will be the same and you wont lose any features.
Keep in mind that there is the door latch recall, you wont know if the donor door has the updated latch, If you have already had the recall done I would recommend swapping the latch from the current door to the new door, if you havent had it done then go get it done after you swap the door.
Remove the interior door panel and make sure there isnt any bent/damaged parts in the donor door, if there are you should be able to swap parts from your current door to the new door.