I have a mild cold. My sore throat is gone, just left with the runny nose and a bit tired.

Is it safe for me to just walk(w/ a little bit of running)? I've missed the last few days with the holiday and cold onset. I was hoping this could help get the blood flowing and feel better. Thanks!

Depends how you feel. A little activity could be just the thing, if you're already starting to get better. Just don't do more than you feel up to, and be prepared to cut it short if you start feeling worse. And if you have any fever, don't.