For your age, it is a nice painting. A bit loose in the finer details, but overall quite good! Acrylic is a great media and oils are over-rated. The other thing, is acrylic is much more forgiving and faster. Don't be afraid to keep working into this painting and add more details, clean up your edges and maybe work a bit on your perspective. What is the size? It look fairly large and that is also to your advantage. The one tip I have for painting is always spend money on high quality brushes. The acrylic paint is all pretty much the same and the quality is important, but the tools you actually apply the paint with are vital. A nice detail brush can cost a lot, but it's worth it. Painting with a brush that frays or falls apart quickly sucks. The more you spend on a brush the longer it will last because you will want to take care of it. A good brush cleaning soap is very important to maintain a nice tight point and make it last. I ink with brushes that average $30 per brush and I still use the first I bought about 5 years ago. And it still gives me the fine point and flexibility I demand.
The other thing is don't be afraid to by acrylic gel mediums, extenders or liquifying agents/mediums. Do not use water and acrylic unless you want a watercolor effect or to clean your brush. For details, the water just makes the paint more transluscent. But preliquid (airbrush) acrylic for detail purposes and you never have to worry about the strength of the color or opacity of the paint.
Keep up the painting and continue to share with us!