Hi there!! Super honored to hear that you find the game enjoyable!
The fn/look up and down function is totally optional so if it still doesn't work after few retries it won't be a problem when playing the game so you can not worry about it and proceed, sorry for the confusion/inconvenience!
for me the pg up and pg down buttons worked but not the arrow keys, I figured it out completely on accident since they're so close together but hopefully that helps u figure things out