mobile

Hi guys, I'm pretty new to rooting so tell me if i need to give more info etc cause I know i can be a bit vague.

So I rooted my phone no problem via the all in one kit thing and installed cyanogen, but this was right before the big android update so I wanted to switch back and update to that, but somewhere along the line i got rid of all the Roms (I think)

The stage it's at now: I can boot normally but the startup wizard fails, I assume this is because the stock operating system isnt hooked up to run, regardless I can't find a copy or figure out how to run it. (before my TWRP seemed to stop running on startup)
Bootloader: I don't know how it ended up relocked after I'd unlocked it but am guessing that is why i cant access the custom recovery at the moment (twrp)

If anyone is able could you walk me through, or point me to a guide to show:
How to unlock a relocked phone,
How to get a Stock version of Android (anything after 4.0 I guess because it will auto update?) running on there
Tell me if I'm being dumb in any part of this (apart from pissing about with things I don't understand, haha)