"I have written some code ... outputs a menu ... it does work but is ugly."

Do you mean your code is ugly, or the menu is ugly?

What do you mean by "ugly?"
Beauty being in the eye of the beholder, what would you consider "pretty?"

"...pad each text line with spaces so they are the same length"

Note that this will work only if your terminal is set to use a mono-spaced (ie, not proportional) font; I wouldn't rely on hypoterminal to do this...
(actually, I wouldn't rely on hypoterminal. Period.)

Presumably your PUTSTRING routine currently detects the null byte to mark the end of the string?
I think that's probably better (certainly more flexible) than forcing your strings to a constant length: Using a fixed length means you have to count the characters; just testing for zero needs no counter (and you need to make that test anyway if you're counting!)