Been trying to remember what I learned last time and when I went for my first run it all came flooding back! These are things I wish I'd known at the beginning last time. Hope some of this is useful to you all.
Definitely be careful what you eat - once I got to running for longer periods I avoided eating anything heavy about 4-5 hours before and anything light (like a yogurt) for a couple of hours before. If I didn't I felt really sick and sometimes had to stop cos've retching!
I found it really hard to run in the morning after not eating for 12 hours plus and preferred to run at tea time but my husband is the opposite. It made a huge difference to how much we struggled depending on when we ran. See which time suits you best.
If you're struggling walk as long as you need to then just carry on as if you'd be following it all along. It makes little difference to the calories burned as long as you keep up a fast walk. Some people repeated sessions or even weeks but I managed to move on, even when I had a bad session, as I had mentally set the target of 8 weeks to 5k. If I'd struggled for 2 or 3 runs in a row I would have done that.
I started on hilly ground which was really tough, when I switched to flat runs it was SOOO much easier. I think that's why I didn't give up!
People run VERY different paces so cover different distances in the time. That meant some people covered the 5k well before the end of the 8 weeks. Wasn't a good idea to try to keep up with them when I'm a slow runner as I totally overdid it and felt ill. In the end just moving in a sort of trot for the required time was enough! I always found the first 10 mins hard going then sort of got into my flow (plus knew I was almost half way through after that!). Remembering that and reminding myself it would ease up in a bit made starting each run a bit easier.
I started off with the NHS app but found the music irritating. There are lots of free or cheap C25k apps out there that allow you to use your own music and will interject with instructions when needed. There are lots of guidelines out there for which music is good to run to if you are THAT into it!
I liked measuring my runs to see how far I'd gone. Sometimes when I thought I'd had a bad run it was actually good because of the distance I'd managed to cover. Map my run is a good app for that.
I didn't diet but just naturally ate a bit better I suppose as I was enjoying shaping up. Plus avoiding eating before a run meant I nibbled less.