[Not running 10min miles]

I wish I was doing a 13 minute mile lol. I'm running a 16 minute mile but as big as I am I'll take whatever I can get. Just keep getting out there and push yourself a little harder every week eventually you'll get your distance up which will bring your time down. I know that's not super helpful but it's different for everyone.

[Do you run heel striking first or ball of foot?]

Neither! Both are really hard on your muscles and joints you want nice even strides landing on the flat of your foot. Think of your foot as a shock absorber the bigger the surface you land on the more shock from the impact gets absorbed. I hope this helps!