Not bad for a first try. The melodies are nice. However, you definitely have to work on how to arrange all instruments together. Once the other instruments start playing, they don't fit together very well. It sounds a bit like a cacophony. Also, it would be nice if the melody was more varied. Especially in that first part. It should be changing at least a bit. Right now it sounds too repetitive. Seems like you have a good knack for catchy melodies, so you should capitalize on that and make them even better.