I have already made a couple posts and my profile won't let me create a bio. There's no 'edit button.'

<Snipped quote by Rosebudxo>

Add an avatar and it solves your issue.

<Snipped quote by Kuro>

Thanks! But how do I add an avatar? And does someone on the forum know how to resize a photo, etc. ?

<Snipped quote by Rosebudxo>

Click the edit button on your profile page and scroll down to the avatar section to upload an avatar. If you need something resized, just google image resizer or resize it in an image editing program like Gimp, paint, etc. If you're needing it for an avatar, though, there's no need to resize it since the guild automatically resizes it.