Go to a specialist running shop for the trainers; being heavier and building up to hour+ runs, a well fitted pair will help ward off niggles.
Good sports bra is a must.
It's worth having a sports watch too. Garmin is a good value, practical brand (others avaliable). I'm currently working on a training plan on my watch with the sessions on the screen, and it instructs based on heart rate/ time/ distance which is useful. When doing out and back routes, pre-programming the distance to know where my turning point is is very useful. They're also good for getting objective information on pace/ heart rate so you can see how much effort you're putting in (and if you need to back off). I like to record my runs in a book so I can see progress and patterns, and refer back to routes. Watches are quite easy to get second hand particularly since Garmin has a newish entry level of watch.
C25k is the hardest stage of running- I first did it post-baby, and was back on it this time last year due to injury recovery and in 12m I've gone from wk2 of C25k to Jeffing a marathon in a "running" time. Originally it took me a while to get to 5k (mostly to do with a young baby, winter illness and starting a new job) and then I signed up for a 14k fun run intending to run/ walk and accidentally ran it all and got talked into a HM in a post run high. They were 3 & 6m after completing C25k and there were lulls in that time.
Once your body is adapted to running for 30 mins, it's relatively easy to add time/ distance on. Just use a proper training plan that considers rest weeks of reduced time on feet. Also have a gentle week just before the event.
Don't save parkrun until the end, you can walk, run/ walk, run as you need and it's a good introduction to organised events.
Warm-up and cool down. I stretch off on the doorstep after the run. Warming up is gently using a range of movement to prepare your muscles. There's loads of 5 minute videos on youtube.
Strength work is also helpful at warding off niggles. Fortunately that doesn't have to mean special body building sessions at the gym; short frequent body weight sesions/ yoga/ pilates all help. Even just building some exercises into your warm up/ cool down routine for a few minutes can help strengthen weaker muscles without too much additional load of time and effort.
It is a sensible, acheivable goal that can be met with a well planned schedule, basic gear, and a determined but open mind. Good luck!