I may be being stupid, but I really can't figure out how to do something on my computer, and I'm getting stressed.

Basically, I downloaded a job application form off a website. It's in PDF format, and read-only (as in, when you click on it, the little hand grabs at nothing). The form filling-in guide says that you can fill in the form either by typing or in pen. I wanted to type it out, but how can I if it's read only? I've saved a copy, and I still can't edit that. I can select the text and paste it into word, but then it fucks up the formatting and won't copy the boxes etc. Is there anything I can do, or do I just have to fill it in in pen?

Thanks.