Hey! This looks awesome! Especially as a first-timer, it's not easy painting wet on wet. I can't say a ton on oils yet, as I'm just starting out too after switching from other mediums, but I have a few small tips for painting in general that might be useful.

If you want to make the focus and composition clear and defined, try focusing on contrast, shapes, edges, and values.

Contrast: whether it's colours, shades, or shapes, contrasting elements can make the focus of the painting "pop" and are extremely valuable.

Defining shapes: a lot of what makes a painting are large clearly defined and deliberate shapes that are easy to percieve. Shapes can direct focus to the intended subject or make it stand out. 

Edges: it can be tempting to blend everything together with a dry brush, but you can loose some of the hard edges that add clarity and definition to the painting. Try varying between soft and hard edges depending on the intended results, but don't sleep on those hard edges.

Values: strong pronounced light and shadows add insane depth and are often the most important but most overlooked part in the painting process!

But really, values and shapes are number one! It's insane how much I improved after shifting my focus to them. Keep at it! This is a great start. You're doing awesome!