Welcome to the forum and well done on getting started.
The guide linked to by Instructor57 will give you basic advice but if you want more detail this FAQ Post about breathing gives more details healthunlocked.com/couchto5... but basically....,....... relax and slow down.
Congratulations on making a great start! I really like something one of the Nike coaches says about running-measure success in as many ways as you can find. It’s not just about how far and how fast. That feeling of positivity is such a massive one to celebrate.
I agree with the advice about breathing-slow down and it will get better. It’s such a great feeling when you find that conversational pace and it’s absolutely worth putting in the effort to learn to go slowly as early as possible. It’s the most important thing you can do for your running!
Re breathing - don't worry too much about it. Just keep your pace slow and conversational. You will read and hear advice about breathing in through your nose and out through your mouth and also about counting a certain number of steps to every breath but don't get hung up on it all. Some people find it helpful but others struggle with it - we're all different. The main thing is just to remember to breath regularly!
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