That’s a great question and I really admire your learner mentality! I will preface my answer by saying I don’t know exactly where you are in your music-making journey and I don’t know what you already know, so I am only making assumptions based on this one track. I would say that based on your selection of the “beginner” category, it would be reasonable to suggest some basic concepts. My perspective on music theory is that it is an extremely useful construct to guide and understand choices made when music is written, but there is a reason it’s called music THEORY and not music LAW. While no one should ever feel completely confined to the “rules” that are taught in theory classes (I subscribe to the philosophy that music that sounds good, is good), it is an excellent place to start to guide what to learn next in your composing journey. Because of the constructive feedback I noted, I would say looking into how harmony works at a basic level would be my suggestion for what to learn more about next. Based on your B section, I will also assume that you might already know some about harmony or your intuition is spectacular (or both). So specifically I would focus on how basslines work as they relate to harmony. Often, we are taught that the bassline is the movement between the root note of the different chords of the song. This is a very simplified idea and the bass does not have to function this way all the time (music would sound boring if so), but understanding how the bass connects to the chords you use in your music and how to use the bass to help move from one chord to the next chord is a fundamental building block for composing. You don’t have to have many chords in a song for it to sound interesting - the track “Let It Ride” from this jam at its core only uses two chords, and I think it is a really creative and interesting track. There is lots of variation in how those chords move back and forth from each other and that variation is what keeps the listener from feeling stagnant or bored. 

I feel like I may be rambling at this point, but the bottom line is you are doing exactly what you need to do to get better - write music and ask for feedback! When I participate in jams like these, no matter if it’s the composer’s first song or 300th song, I try to listen very intently and take something away from the choices that they made. By offering what I liked most about the track, I am subconsciously creating a framework in my mind of which elements I want to add to my own palette of composing tools. And conversely, by offering feedback, I am practicing noticing where things can be improved so that I can apply the same degree of perspective to my own writing. I would highly encourage you to listen to every track closely in all jams you participate in! You don’t need to comment all of your thoughts, but having some intentionality behind listening is one way we can grow from each other. I hope this is somewhat helpful and/or at least somewhat the direction your question was oriented. I’m always happy to chat more about music and music education philosophy if you have more questions/thoughts in the future!