Travel south west. Maps work just like a normal world map would. Top is north, right is east, bottom is south and left is west. In this case you are in the upper right, so you would need to travel to the bottom (south) left (west).
There are three types of explorer maps: woodland, ocean, and buried treasure. The maps differ from a normal map, in that it shows the area's land-water outline, as well as an orange striated (striped) texture for areas below sea level, and the blank map texture for land above sea level. The maps show a section of land that contains a woodland mansion, monument or buried treasure respectively. This may not be the nearest such structure to the player. The structures are displayed as a small icon. If the player icon is smaller than it would be on a normal map, that means the player is a great distance away. When the player is less than 1027 blocks away from the map border, the icon returns to the proper size. When the player reaches the map's area of land (512×512), the map fills in like a normal map
I'm only playing 1.13.2, but i dont think anything has changed, in short they are quite rare, and the only one I have found in my world was approx 2000 blocks west and 14600 blocks North from spawn! Luckily mine was nearly the max size you can find; they do vary. Good luck!