Hi Kimberley!
You're all set now! So glad to have you here to play along with us!
To edit the original post, you should be able to just go back to where the post is and hit the "edit" button at the bottom of the post to the right.
To add your photos, you'll need to have the photo hosted elsewhere (like photobucket if it's a photo or our gallery here if it's a layout). When you're typing your post, you'll see a little yellow box with a mountain in it directly above the area where you type. That's the "insert image" option. Click that, and when the box pops up, you'll put in the URL for your image (it should end in .jpg or .png). This will insert it into your image with the codes wrapped around it.
[URL="https://www.sweetshoppedesigns.com/tutorials/index.php/2012/07/how-to-link-images-in-the-forum/"]Here is a tutorial[/URL] that you might find helpful.
Also, until you have 10 posts, even though I've got you fixed up with permissions, the forum gets a little quirky and doesn't like it when new people post images. So, when you post an image, it may tell you that it needs to be approved. I look for those and try to approve them as I see them, but if I miss it, you're welcome to send me a private message. This shouldn't be an issue after 10 posts. You can comment on threads, start your own, or comment in the gallery to get your post count up, too. :)
I hope that answers your questions! Let us know if you need more help. The girls here are always happy to welcome new members, and we don't mind answering any questions you may have!