Hi everyone, I've been a bit slack about joining the forum here, so I'm already quite far down the road.
I think the main thing I've learnt by doing the program is that, on the physical level, everything depends on your core. When I first started, I eventually ended up with continual back pain. It wasn't unbearable, but it was definitely very uncomfortable. What I did was reverse back down from where I'd progressed to (Week 4, I think), cut back on anything in gym that felt like it had the slightest impact on my back, and searched YouTube for stomach exercises suitable for someone with a sore back.
The ones that worked for me in the end were the ones where you bring up your knees, and then try to lift your bum off the floor with your stomach; and the similar "curled up on your back" one where you sort of bicycle toward your elbows. Combining those with reduced running ambitions sorted out the back pain, and allowed me to move forward.
From your point of view, if you're new to this, the way you could make use of this back pain of mine is probably just to remember that there's nothing preventing you from just doing week 1 over and over again. There's no hurry. (And right now, I'm doing I think my third repeat of week 5, while I wait for my hip to stop hurting. It's a core thing again. Years of core neglect take time to fix. At this stage there's no need for me to reverse back down to week 4, but that's always an option.)
The final initial input I can offer is that I think it's worth waiting for a bit of speed to develop, rather than just building up the ability to shuffle along for 30 minutes. There's a certain speed at which running feels nice, and it's not the shuffle (unless you're having a little mid-run break from overdoing it when you started). I spent a long time on week 3, just trying to go a bit faster in at least the first runs, and that worked for me. You're not me, so something else might work better for you. What will always work the same for the both of us is if both adapt the program so that it's enjoyable.
OK, so then there's actually One More final final input. Try to believe this: You can ENJOY your runs. Make your program fit You, and you will get to the point where you actually Look Forward to running. I know that sounds impossible (I certainly would have had a hard time believing that when I started), but you can Enjoy this.