Advice for new runners?

if i do that i dont get enough oxygen.
my way is breath in through both nose and mouth and exhale the same way.

What exactly happens when you breathe out through your mouth that doesn't happen when you breathe out through your nose?

I ballooned up to about 235-240, and I'm 6' so probably exactly where you're at. There might be some good replies, but I can tell you as somebody that actually went from that to being able to run miles and miles -if you aren't in good shape (no cardio conditioning) you're MUCH better off with a fast walk for 20-30 min a day for a month at least. Spending a hundred bucks on a heart rate monitor will get you really good results if you use it. Another good way to go is HIIT (High-intensity interval training). You just run for maybe 30 seconds as fast as you can and then walk for 30 seconds (the actual intervals can be different than that. Going that way is a massive calorie burner and it also contributes to increasing testosterone levels, which is going to give you all kinds of boost in the weight loss dept. If you're always running at your max effort then you're not going to be burning many fat calories, so whichever way you go you have to make sure you're not pushing yourself harder than you need to. A heart rate monitor is invaluable for measuring that.

As an avid runner, I will recommend against running unless you either:

A) genuinely love to run, and will pursue it as a sport or hobby.

B) running is a featured activity in your profession, i.e. law enforcement, military.

You may want to see a doctor about that.
It's slightly more delayed, humans don't absorb oxygen all at one time. It just gets a good rythym for absorbing more and more oxygen. You can even do 2 inhales through the nose then one exhale through the mouth for even more oxygen. Also you can inhale and exhale at the same time if you aren't legally retarded.

Go hiking through a very hilly area.

You'll build up your VO2 efficiency.