Not sure if I'm walking too fast and running too slow or the other way around.

I know the whole "whatever is comfortable for you" line.  But I want to know what others are doing.
I walk at 2.5, run at 3.5. I've been told to run slowly, that you should be able to carry on a conversation and not huffing and puffing. I'm going to keep at this pace and then once I finish start to increase my pace then. I don't want to go too fast and hurt myself or get too tired too quickly and quit. Any running is better than no running.