Do you know how I can change the font or font size in just a portion of a note? I tried highlighting a portion of the text in text editor and changed the font size but the whole note's font size changed.
You will have to seperate the text that requires a different font size. When you right-click the text, select Properties and edit the TEXT file as below (example):
The note "text" is originally shown as:
{0:text}
now it becomes
{0:te}{1:xt}
Now you can change the "te" and "xt" independantly of each other.