Even if I have wifi as well as the network, I'm still unable to send photos. I don't have data with my plan, but it says I have unlimited text and picture messaging and unlimited SMS. If you know what's going on please help thanks :)
Since you do no have data (3G) the only message pictures you will send are those sent through iMessage. MMS needs cellular data in order to work. What you could do if you want to send a non-iMesage MMS, you would need to connect to a wifi-network. Activate cellular data. Send the picture. Close cellular data back.
Or, you could download an app like WhatsApp to send your MMS through wifi.
I know it is pretty confusing that you get unlimited MMS, but you actually need to have a data package. This is how it works.