Hey sliceofmeat1, and a belated welcome to the guild!
Great to see the start of your journey into mapping. I like the overall layout of your town and can only agree with UrbaNick6 on the helpfulness of a narrative or a sort of a "golden thread" guiding your planning/drawing.
For me it always depends when to use a ruler. Sometimes i like the "not so straight" hand drawn lines better, sometimes the buildings have to have a clean cut. Again it mainly depends on the narrative or the purpose of the place/the map.
Since you asked about the trees and the river. The general form of your trees looks pretty fine. Only the details look a bit too random to me. When drawing top-down trees many people around here, like to draw the tree's details following the outline concentrically as shown in the image below.
The waves on the river seem to indicate a sideview or a isometric perspective, while the buildings and trees are clearly in a top down perspective. That's why i'd suggest to draw the river's details along the riverbanks/the stream. (Imo, the larger the scale, the more important it is not to mix up the perspectives of the elements)
treeandriver.jpg
For city/town mapsn in general, i recommend to have a look at the lovely maps by
Larb. She has even created an award-winning
Town Map Tutorial. It's written for Photoshop, but the linework is easily adaptable to hand-drawn pen&paper maps.
I hope i could help a bit. Looking forward to see more of your work!
Cheers,
AL