Note - this is for a prototype logo!
Step 1:
Open Keynote.
Step 2:
Pick a designer font. From the font collection that was shared or these other free font resources.
Step 3:
Write your name in that font.
Play with the font spacing (making the letters closer together) if you desire.
Make the text nice and large so that your logo is an appropriate size (300x70 is a good rough size if you aren't sure), and then take a screenshot.
(Optional: make the image transparent)