You don’t need to Show() widgets on creation as they are shown by default but:
tf.Text = f:CreateFontString("Bazooka")
is using f to create the fontstring. This should generate an error unless you have assigned a local f (or global f) using CreateFrame elsewhere in the code.
Change f to tf
Also, you’re anchoring the frame to the CENTER of UIParent but not anchoring the FontString to anything
The FontString will default to the size of the text or if a size is set will wrap or terminate with a … depending on the text length vs FontString size.