Since you are new to quilting have you done a quilt on point before? They are a bit tricky because you need to figure out the size for your setting triangles. Also did you pre wash our fabrics that you bought with a color catcher? Red especially will more than likely bleed. I am speaking from experience. I love the reds you are using because color popping all over sprinkled through out the entire quilt adds dimention and movement. There are so many ways to sash the blocks. I really like the block that alternates with what you have . I am not sure of the name but it is like a chain and striking to look at and I think it would be wonderful in this quilt without making it too busy.
You are on a great start I think your son is gonna love what you are doing! Be patient and take your time. It is gonna be awesome!!! :thumbup: :D :thumbup:
I hope I have helped you out!
Have a great day :D