I have been doing couch to 5k on a treadmill I find it gives less impact on knees and ankles.
But as I have got to W7 R2 thought I might have a go at the big outdoors. Any advice on if I should invest in a proper pair of trainers and a reasonably priced pair would be great.
You don't need much posh kit to be a runner, but you do need decent footwear. Good shoes are essential to protect your joints. Unfortunately, 'gait analysis' is not an option at the moment, which is usually the way to go.
If you are confident that you know your size in trainers, its worth looking at the old stock, which are often reduced. Even online, I would always try and support independent running shops- now more than ever!
Enjoy the great out doors- so much more fun 
Yes definitely invest in decent trainers going from a treadmill to tarmac or pavement is completely different I would also advise running socks this sounds odd but they really help, the trainers don’t need to be expensive but a decent insole is worth investment in as well . Like you saw the treadmill gives less impact so definitely get outside but prepare as it is completely different let me know how you get on good luck! And remember to enjoy it
Hello. Well done. Hope to be where you are one day. I'd say good foot wear is important. Do you use trainers on the treadmill? Comfortable and sterdy/bouncy. Are kind of ones I run in. I don't buy these for running I had them already tho x
You will notice significantly more impact if you run outdoors. Grass will give less impact than concrete but is also more energy sapping.
It may take you a few runs to get used to being outdoors so don't get disheartened and keep your pace very slow.
Pacing, gradients, weather and uneven surfaces take some getting used to it is real running, in my view, so worth the effort.
This post about running shoes may be helpful healthunlocked.com/couchto5...
Treadmill?
Treadmill 
Treadmill? 
