Congratulations Ellen on your stepping OUT!!
I am one who writes a lot, so starting a record of all my "outings" or "sessions" came naturally to me and helped me loads cos improvement can be quite dramatic in the first few weeks & months
Firstly I had no-one to go out with - the idea of running came from my sister who was already a RUNNER - but living 300 miles away! but also I was not at all slim and felt a bit foolish, but it was just great to go out (I'm fortunate to live in a scenic coastal area) with just a bottle of water and a key!!
But I did have a GOAL of a 5-mile race which was 9 weeks away. After the second week of "starting running" I decided to do 5 miles - mostly walking ofcourse at that stage, it took me 80 mins and included some running. It was a hot day and when I got home my face was bright red & my HR stayed at 100 for quite a while ... I was 11 stone 8lbs and my RHR was 76.
I timed everything and tried to measure distances too. I checked my pulse in the morning and weight once a week. Although later I realised measuring my shape would have been more helpful as muscle weighs heavier than fat, so as you tone up, your wobble goes and your shape changes - whoops, well I had quite a lot of wobble ... !
Things improved - and I found having a record of my own Times over the same routes was a HUGE encouragement, I am now trying to work on ways to help beginners in the WRN (womens running network) and I would say WALK a lot too, even once you are able to run further continuously ...
do you do any other exercise? cycling, swimming, dancing?