Matthew,
Let me be the first to comment you. Congratulations on the effort!
I am sure that at age 13 you don't have a lot of material at hand like us older ones, so it is difficult to advise.
If you really have a Sherman to put behing the Jeep, than you should at least get rid of a good amount of space to the right of the Jeep, because there is to much empty space.
The latern (is it scratched?) is a bit out of scale, a thinner dowel and also a rougher kind of wood would be better suited.
Regarding the cork, it is difficult to say something as it is not really recognizable . what this is really. Is that supposed to be moss between the stones? Why are they so strangely positioned?
Try to get some thin cork and scratch your road the next time. It will look better and you will have done something yourself. There is plenty on this forum about cork cobbles, it is very easy and cheap.
I will leave the comments about the Jeep and figures to others.
I am not sure if you should already buy expensive resin figures until you have better paint results. Stay with Dragon for now, they are good and cheaper for training.
Cheers
Claude