Pick a voice you like.
Pick music you enjoy and will make you feel positive. It doesn't have to be fast and pacey because you just need to get your body through a running motion for the block required. Run slow. Just keep running. You're not trying to impress a PE teacher.
Week 5 & 6... trust the plan. It builds up the running time. There comes a scary moment where you run for something like 20 mins... but you'd already run for more than that, it's just the walk blocks reducing. You will be ready.
C25k tends to be a bit of a misnomer. Really it's C230mins. Many runners don't reach 5k in that 30 mins, and that's fine.
Wear layers. I found it helpful to do my warm-up around the block and chuck surplus layers into my front garden as I passed by. Over time you'll get to know what you need to wear for the run you're about to do.
Have comfortable, recent trainers. You don't need £££ specialist pairs at this stage, but you do need trainers designed for running to aborb the impact.
Some runs will be hard. It might be weather, mood, energy, hydration, food, hormones or something totally random. It doesn't mean that you're not progressing or that the next run will suck. It happens to all runners and experience is acknowledging any useful reason/ pattern and learning from it, or brushing it off as one of those things if it is random.
When you start running, you become a runner. If you want to do something like parkrun, a race or join a club, go for it and don't hold yourself back.