I agree with Zoe that being moderate with goals is a good way to succeed. Maybe have a "short-term" goal as part of a bigger "long-term" plan and use incremental goals as a way to measure your progress? I think a journal is a good idea but don't beat yourself up if you miss days.
I have a problem doing journals as I want to write *everything* down and they take on a life of their own and quickly become such a chore I bail out of them and then feel badly about it. I was hugely stressed out by having to log my numbers when I got my pump but, at that point in time, the pump was my long-term goal and I knew I had to write stuff down. Actually my first thought was "I'll just make it up..." but then, when I contemplated doing that, I realized that writing down IRL stuff would be easier than fiction.
One other thing I'd suggest would be to go to a running store to get shoes if walkiing/ running/ zumba or whatever is part of "active." I did that when I started getting active, got good shoes to walk around the neighborhood in. After a couple of years of that, I was ready to start running and the 275lb AR shoes caused horrible shin splints, so I went back and found some new shoes. I like to go to a store with a treadmill and try different shoes on each foot and run but I like to have comfy shoes.
I had lunch w/ my parents one day and both of them mentioned needing new shoes so I dragged them there and they helped them a lot. My dad has a lot of issues w/ his feet (wide, plantar fascitis) and the person at the running store was running into some issues fitting him and suggested moving up 1/2 size and he's reported that to have been a great solution for him that his podiatrist hadn't come up with that, in turn, has helped him stay as active as he can at 70. I was very glad I suggested it to them and maybe that can help you!