Is this piece meant to be short?
There no indication of dynamics in the score. Same problem with Handel's Messiah. (Should we begin loud or soft?)
Please watch out for flutes in low register (Bar 1 - 4). They will be easily covered.
Bar 15: Watch out for the notes played by Trombones. Maybe too fast for them to be played, may have to check their positions. Otherwise possible, the notes may not be cleanly executed.
Last Bar: Bass Trombone playing a note higher than the Trombone 1,2? Reason? Does it make it sound different? Do you need your Tuba to play such a high note? Rational?
Since, I assume that you have just started a piece, perhaps you could try sketching out the rest of the music, how you intend the piece to be, then aim to create variety in your orchestration. It is still too early to see your potential based on these few bars.
Happy composing.