I picked up my complete RRA lower receiver over the weekend, that I bought right here on the EE, I have the bolt/carrier, and I have a complete upper on order. I also bought a charging handle seperately. Maybe this is a stupid question, but being new to AR's and only having a complete lower with me as a reference, what will I have to do with this charging handle? Is it simple to install? Should I just have gotten one with my upper to make things easier?

You just put it in when you put in the bolt carrier.  There is nothing to install.  You will laugh when you see how easy it is.

very simple to install a charging handle..only will fit one way. slide it in and go shoot.

Turn upper reciever upside down.

Turn charging handle upside down.

Insert charging handle into upper and drag backwards - gravity will install it for you.

After it drops into place push forward a little bit and install the bolt carrier group.

Reverse to remove.