Help with illustrator

Hi all, I'm very new to Illustrator but I'm starting to design my own crash helmets. I'm half way through my design but I have a question.

1.) What is the best way to get brand logos on my designs? I drew a brand logo in a different file, tried to copy onto my current design and it appeared but it wasn't in any of the layers so I couldn't change colour etc. Am I doing something wrong?

thanks