Welcome, and nice work for a first submission. As YoshiGuy said above, when submitting, please link a YouTube video, or whatever primary source you used to make the arrangement. This makes it so people can more easily compare your arrangement to the original, and ensures that there is no confusion as to what variant of the piece was used (when applicable).
You don’t have to write a character indication, but I just wanted to point out that it’s an option to include one.
I assume this is because you use MuseScore or something, but the .mus is kind of messed up. For instance, all the second layer rests are in their default position, which means they often clip with other layers, etc.
A lot of your ties are the wrong direction (right hand opening measures, left hand measure 21, etc.), though this is fixed in the .mus because of Finale’s automatic correction. Barring any layer shenanigans, ties for notes on the third line and above should arc upwards; those below the third line should arc downards.
Generally we avoid using harmonic intervals greater than the octave. While I can comfortably play the opening Gmin(add9) chord, I know there are people who would struggle with it, and the following F and Eb chords are simply impossible for anyone who doesn’t have Rachmaninoff’s hands. You can keep the Gmin(add9) as is if you want, but I would recommend raising the bottom note of the other chords by an octave so all of the notes fit within one octave.
The final Gb in the bass should be written F#. (Notice how it resolves up to G natural when it loops?)
It should be fairly simple to make this fit on two pages. Instead of resizing the entire sheet, try changing the staff height to 7 mm or 6.5 mm and tinkering with the distance between systems.