Been playing around with my phone... just as everyone who's part of these forums loves to do.
Managed to root and install TWRP. My stock ROM was taking up a lot of space so i backed it up to external SD. Then removed the SD and did a deletion of everything on the stock ROM through TWRP. (This is where I believe I made my mistake).
I loaded a ROM to Partition 1 and seemed to install OK.
Now I'm unable to boot past the 'Samsung Galaxy Note 3 - Custom" screen.
Did a bit of research and was able to hold power - vol up - and home and get into the options there but I'm not sure which options I should use within here.
I'm not too familiar with ADB (or other routes of fixing) but if someone could point me to a tutorial or assist it'd be much appreciated.