I see in the score that it is written for 2 oboes, I would like to see it either written for one oboe, or to have more counterpoint between the oboes.
Assuming you want a classical/baroque feel, here is my suggestions:
*In measure 2 in Violin I & II, they have parallel motion by unison with the oboe. I would try to avoid that by making a counter-melody in the Violins. Same thing happens again in m5, 6, 34-39, and 41. In measure 40, beat 4 you have a perfect 5 going down to a diminished 5th, which I think is acceptable, but even if it is or not, I would like it to resolve, tritones love to resolve.
Try to go for even-numbered phrases(preferable 4 or 8), your opening melody is 2 bars long, so use another 2 measure of filler, maybe you can introduce variations of the theme in the filler, or just straight 8th notes, whatever you want.
In measure 4 in Violin I & II , you have an interesting voice-swap/cross-voicing, which is unnecessary. It unnecessary because you don't have a melodic reason to cross-voice, and it doesn't change the nature of the chord.
*Measure 20 in the oboe, you have a dotted eighth followed another dotted eighth note followed by an eighth note. It should really be a dotted eighth followed by 16th tied to another 8th note followed by 8th note. The way you notated it makes it difficult to read for musicians.
You need to work on the cadence at the end, generally you want to end on the i or I or V(I would only use V if you know how to make it sound conclusive). Starting from measure 43 you have this chord progression: v -> VII -> i6 -> i
It is a weak final cadence. You want something more like: V V7 i(or I) It is much stronger.
The chord changes should really be on the strong beat.
Overall, this is a really good attempt. I think you are just starting to compose(am I wrong?), if you are, you are better than when I started. If you weren't going for a classical style, then ignore everything above except for the parts marked with a '*'.
I would try to learn about chord progression and voice leading from any music theory site, here is an English one:
http://davesmey.com/theory/partwritingrules.pdf
I hope this helps.