Catherine,
Just want to add my welcome to the rest. This really is the best place to come for advice (both professional and anecdotal - I'm afraid you only get the second type from me!)
With that in mind, I think you have made a great start with your treadmill work and your target of 10K is easily achieveable. However, it's easy to get hooked and build up too quickly, which inevitably leads to injury (in my case, shin splints).
Just take your time and keep posting on the forum, good luck!