I have taken up running. So is a mile of jogging and walking too much of a warm up?

For my regular runs I don't really do any kind of warm up. If I am doing speed work of any kind then a mile would be sufficient.

I'm answering this a bit late so I should ask: are you still running?

That's a great start ... before you know it you'll be doing more and running the whole way .. suggestion if you're in good health ... set a goal of doing a 5K in 3-6 months and work towards it.

Plenty of them that are non-competitive ... a lot of them are lots of fun and for some charity ... pick one for a cause you care about ... some extra motivation !!! I do the local Susan B Komen Breast Cancer run every year.

Nope! When I was in cross country, we had to run a mile for warm up everyday

I did a 2 mile warm up today.

1 mile sounds good

That's actually a great start, pretty soon you'll work your way to 5 miles. :-)