I think it's really good you have FL now! I heavily recommend learning a few basic keyboard shortcuts (especially ctrl+B, ie quick duplicate. Saves so much time) A long term tip for learning is to watch tutorials for everything. There's a ton of them for genres, just look up "[genre] tutorial fl studio" or whatever and you'll get high quality walkthroughs.
Another tip that helped me a lot with music theory is to remix a lot of songs you like. You'll subconciously study how the melody and chords are made and that will help you make your own.
Objectively, the song itself is pretty average, but for a 2nd ever song in FL, it's really good. I know you already have experience with FL mobile, but most people's first song is a questionable drum beat lol
Keep learning and good luck with FLS!