There is no point in trying to pad it out if you haven’t done much, though. We’ve been graduates with not much to write about as well. We can see through any ‘padding out’ .
You are spot on about proof reading and keeping it clean and clear though. This is an important skill for a designer to have. When you are sending tech packs to a Chinese factory, you will benefit if you can get things across in a clear way. If your resume reads clearly, it’s going to give your employer confidence in your abilities to communicate effectively.