I understood that 'credits' means parts from your drawings. Am i right?
Credits means basicly who drawn the ship. We use rather simple method to credit the artist in our drawings, by placing the name under the name of the ship in brackets.
If you drew it all alone from the start, then you credit only you self. If you "kitbash" eq. use parts of other's drawings or had someone to co-work with you, then you credit them as well after your name under the ship's name.
If you modify existing drawing, then you add your own name after the orginal artist name.
If you use Paint, then the font sizes should be 11 for the ship and 9 for the name (otherwise follow the template instructions.)