Basically if you watch the short clip below I am trying to move a video around from one side to the other but I dont want the black space between I just want whatever it is visible to be the actual video, I tried with the ken burns tool but i couldnt modify the aspect ratio https://drive.google.com/file/d/1o7RilS_iQEJTLb2I_sHvh1_3UQL4S05x/view?usp=sharing

From the video and your description I'm not sure exactly what you're trying to do there, but I'll link the thread to one of our Final Cut Pro courses—hopefully a real FCP guru will understand and be able to offer some advice.. :-)

So the video is 4:3 and I want to cut it to 2:3 aspect ratio but I want to show first the side with the reference which then moves to the actual drawing, kinda like a ken burns effect but I couldnt do it that way because because the aspect ratio is locked (Ive put a link with a picture). So I tried using a trim key frame to move from one side to the other like in that clip but it wont cut the video, it will just hide rest and make it black. So ideally in the end I want a 2:3 video that starts with showing the reference and then moves on to the timelapse of the drawing. Sorry if I'm not explaining it properly, i'm kinda new to this software. Thanks! https://drive.google.com/file/d/1c5W_tB5Jxy--VUJYkNlT5kUc47hxa4TP/view?usp=sharing

This is an easy one. Don't use Crop at all. Use Transform, and make the scale bigger, to fill the screen. Move the video over to one side, then add a keyframe when you want it to start moving. Move to when you want the movement to finish, then move the video over, and a second keyframe will be created automatically.

:)) I knew it was something simple I missed.. thank you so much!