This will probably be the only filter you’ll need to use. If you want to position the video left or right from center. Either move it with the center dot, or enter the values, keeping the 2nd value at 0 for vertical center.
This filter, with the Position can also be used with KeyFrames for even further manipulation. There are many posts in this forum for Keyframes.
As I was going through your video, I saw that you actually had 3 different video sizes not just 2. The title cards you have near the start and at the end of your video were of a different size than your 16:9 and your 9:16 footage. I treated those parts accordingly to make it fit.
I can only check this on my mobile right now and can only do this tomorrow (I´ll be at my gf´s house tonight) - but i think you hit the mark. Thanks so much for doing this!
In any case: the video is now live on yt - thanks to your and Hudsons help. You helped me a lot with understanding the program better and I guess my future videos will be edited much better because of that.