I am guessing that my file structure is wrong because the "assets" folder does not show up in "Android" mode and only shows up in "Project Mode"
According to your screenshots, you do not have an "assets" folder. You have a res/assets.fonts/ folder. It has the wrong name (assets.fonts, not assets) and is in the wrong location (a child of res/).
Step #1: In your project tree, right-click over main.
Step #2: Choose New > Directory from the context menu that appears when you right-clicked.
Step #3: In the resulting dialog, type assets, then click OK. You will now have an assets/ directory under main.
Step #4: In your project tree, right-click over your newly-created assets directory.
Step #5: Choose New > Directory from the context menu that appears when you right-clicked.
Step #6: In the resulting dialog, type 'fonts', then click OK. You will now have an assets/fonts/ directory under main.
Step #7: Drag your font file from its current location to move it into assets/fonts/.
Step #8: Delete the res/assets.fonts/ directory, which is now empty.