mobile

NOOB ALERT!

I have a samsung sgh-i747 that is still tied to the AT&T network, although, I do not have a SIM or service anymore. (is not being unlocked my issue?) I have been trying install Cyanogen 11 and 10.1. I currently have TWRP recovery, and the phone is definitely rooted. I have followed multiple guides to install a custom OS and nothing has worked. When trying the first time, I get the status 7 error, then I remove the assert check from the script and it still fails. It will sometimes just fail right after it skips the md5 check and not even return an error. What could I be doing wrong?

Possibly relevant info:
- I have CWM recovery that I installed TWRP over(may not be an issue, idk)
- I have tried installing .zip from sdcard and sideloading.
- phone is on stock 4.4.2
- I factory reset and wipe cache and dalvik cache before trying to install ROM.
- I have tried installing on TWRP and CWM.

Any suggestions would be great. I am new to the whole rooting and flashing thing, so I wanna get this done because I am slowly becoming obsessed.

Thanks guys!