Congratulations on finishing your first composition, and I'm assuming your first port! However, there's still a bit to go before it can be accepted in the section.
First, the .txt is completely unoptimized. There are a lot of patterns that repeat throughout the song, so it's primordial that you use loops, superloops, and label loops for repeating patterns in order to minimize the insert size as much as possible. While you do have three loops in your song, these are single notes placed in loops, which never repeat, two things that always increase the insert size instead of repeating (save for one exception regarding single notes, which I'll cover later).
Here's an example of how loops work. This is what channel #0 looks like in your .txt:
Using loops, you could shorten it, like this:
This is just one example, and your .txt has many more things that could be looped.
One thing to note is that loops do take a certain amount of space, so looping groups of one or two notes only one or two times often may not be efficient. When in doubt, just run a version of the song with the loop, and one without, in AMK, and compare the insert sizes.
That being said, however, if the pattern is short but repeats a lot of times, i.e. more than 8 times for single notes, like how @23c4 does on channel #3, then you can put the single note in a loop and make it loop a huge number of times. The same logic applies for long rests as well, which are best expressed as loops as r2. For example, [r2]r2r2r2r2r2r2r2 can just be [r2]8.
One last note about optimization, but the t command does not need to be redefined per channel, as it is global. Most ports usually have it once on channel #0, with more t commands only if the tempo changes.
Next, as for the composition itself, I don't want to be an absolute authority on the matter as it is ultimately a question of personal taste, but I feel like it could be better. Going by ear, most of the song sounds like random notes put together. In that regard, I'd suggest brushing up on music theory a little bit, mostly how keys and scales work. As well, the instrument choices make the song sound a little bit loud and jarring in places. @4 is a very loud sample, while @5 (especially in low octaves) and @2 are very situational, and in this case, the three of them don't mesh together very well. I'd recommend playing around with ADSR as well, since it could give the instruments a more refined sound that you're looking for. Following this, the mixing of the channels would need some potential adjustment. Don't forget that you can change the global volume with the w command.
Finally, the SPC tags in the .txt don't actually work in the SPCs, I'd double check that. There's also no need to include an AMK-compatible version, since ports should technically be AMK compatible by default.
Wakana's tutorial and the AddmusicK readme are great references to help improve or fine-tune your porting skills.