Hey @GospelPiano12!
I think starting out with a really simple phrase like this is a great way to start! In my own experience, I've always relied on being able to come up with variations of the main melodic idea that my piece is based on, and in the case of a concerto type of piece, virtuosic variations. Even if your ultimate form isn't going to be a theme and variations, being able to pre-compose various different versions of your main theme will get you far in terms of giving you the ideas you need to put the piece together. So, what you have here is a really great simple idea that you can easily subject to virtuosic variations by inserting notes in between the melody notes you already have:
This could also potentially lead to the formation of ostinati or repeating accompanimental figures which can give your piece some rhythmic drive! Also, since you're writing a concerto for a wind instrument, it's important to remember to give your soloist choice places to breathe. Most of my own concerto type works have been for piano and orchestra. I've written things for Violin and Piano or Violin and Harpsichord, but they were short (and the former, microtonal). I think you can, if you want, use this thread as a place to bounce your ideas off of the community as you make progress. If you're comfortable I can make suggestions like this periodically. I always have more ideas for more variations! Like they said in the movie "Blazing Saddles" - "My mind is a .. a raging torrent! Flooded with rivulets of thought .. cascading into a waterfall of creative alternatives!" LoL