Hey there!
So for the melody, I think it doesn't work with vocals. When it "changes" the vocals, it has to be a little bit more similar to vocals - to give a sense of continuity.
As for the first track ever - congrats, real nice, can't believe it's the first one, since when I made my first track - I put all the effects on master channel, because I didn't know the difference!
So, furthermore about track: synths are not my type - they sound something like from 1990's..
Also, the track really lacks some low end - the kick is present, but the sub is not there, or is super quiet.
The part where vocals and synth are together(around 1 minute), they are conflicting and fighting for the same position and same loudness - vocal should go on top.
And the last thing I'd recommend is effects. It's probably the last thing you think about, but they gotta go behind the sounds and help you raise into 'drop', change parts of melodies and stuff - you use one on 1:00, but it's really hard to understand where is the drop itself, and where it is building for the drop