Welcome to The Guild.
We all feel your frustration at making mountains because we, well most of us, struggle with them continually. I would suggest looking at the Finished Maps section and see if something there inspires you; even if the scale is bigger than what you want you can always make smaller versions. As for the rest I'd say it looks good except for being too yellow - maybe more of a tan would do. On your to do list is get some mountains that you like then put in the rivers, maybe put in some forests if you want (we struggle with those frequently as well) and then do the labeling. You have a good start now ya just gotta do the tweaking...we love tweaking. But don't change the landmass shapes, those are nice.