...It's been too wet to set my posts with concrete so they're in need of shoring up. Any advice on that would be awesome. Also how do people attach metal fencing together at the edges. My best idea is paper clips and pliers?
Posts last longer without the concrete.
Shoring up is bracing... diagonals of some sort are best. Occasionally only a horizontal brace to a second post is done. Often, only the end posts need to be braced.
In your case, I don't think you will need bracing after the posts are set. Until then, I would attach wire from near the top of one post to near the bottom of the next post to make an X between each post. Also, if needed, from the top of an end post to the top of the next to end post on another of the sides. This will brace all directions except in. For that, your choices are guy wires to the outside or something stiff (2x4) at a diagonal to the inside or drive a pipe or rod down beside the post or horizontal legs perpendicular to the post at the bottom if the post.
I would choose the 2x4 on the inside; it doesn't need to go from the top of the post with the light load of a chicken fence - half way up should be overkill. "To the inside" can be one each to the north and east (of the southwest corner) or one to the northwest.
Paperclip idea for a seam is one way to do it or a small spool of wire. The downside is the ends are sharp. It shouldn't bother the chickens; it can scratch you.
Zip ties are fast and don't have sharp ends. The downside is they don't last very long, even with the UV protection.
A stay of some sort (wooden batten or metal strip or rod), in another alternative. You can either sandwhich the wire between two stays if the are strap-like or bend the end of fence around a stay. The downside is it is a lot more visually obvious there is a seam there.
I just bent the wires of one end of fencing around the wires of the other end of the fencing.