First, welcome to the forums.
It seems many have difficulty figuring out how to load a photo when they first try here.
There are other ways but this is how I do it from my hard drive.
First...re-size the pic to no more than 800 on a sice and the quality, if using photoshop, to about 9 when you save.
On the forums, if its in a reply, you will need to click the 'go advanced' button but ;if its a new window then you'll be fine.
Then I click the paper clip at top,(attach files).
T;his brings a window up for you to browse your computer for the shot you want to load.
You can upload up to 5 per post but if in critique forum there should only be one or if related maybe 2 or 3.
Note that under the window there is a check box for uploading to your gallery. If you want it in your gallery, leave it checked but if you don't, then un-check it.
You may upload much larger pics to your gallery. I'm not sure of the size limit there.
Now I anxiously await what you want to post.
They can also be loaded from photobucket or other hosting sites but I don't know how that's done.