How to you make the thingy go over the n in the Spanish n?

You mean this thing: ñ ? It's called an eñe or enye (pronounced EN-yay). To write it, you hold down the alt key and type in 164 -- but it has to be on the number pad on (usually on the right side of the keyboard), not the number line above the keyboard. At least that's the way it is on my keyboard. For the capital letter, hold down the alt key and type in 0209. Warning, it may take a few seconds for the letter to actually appear (not sure why, there must be some calculation that it needs to do).

TLDR version:

Ñ = alt-0209
ñ  = alt-164

Use the num-pad (right side), not the num-line.