I have a couple suggestions that might help.
That being the case lets not worry about your technique or style right now.
Lets focus on design!
What's this character make you think about in the first five seconds?
Viewing things like his stance, clothes and attire, my thoughts roam to an area with few trees, possibly mountains, with South American and Asian influences. Lack of foot attire and an ankle beads tells me his journey may not be far on foot, or he's poor, or possibly on a boat. However nothing about this boy is telling me that he is going fishing. I have not visual reference for that.
Here's some questions to ask and answer for this character's development, "What type of fish does he catch? Large, small, hard to find? And for what purpose? Food, clothing, to sell them for profit at market? Does he use a boat? Does he use a net or pole, or just a string? Or a bow and arrow like south Americans or a spear like an islander?
What experience do you yourself know about game fishing or leisure fishing ? Can you add those elements into your painting to make it a more personal touch?
Try and answer similar questions regarding any new character you design. This way you are going to tell us a story with the image that you produce.