You ask a lot of good questions. FOr 71 you are doing amazing!
TO show your exercise and food trackers from your SPark page, go to the bitton Edit my Page. WHen the editing page opens, look on the right corrner. Make sure Share my food tracker and Share my fitness tracker are checked.
Save your edits at the bottom of the page.
WHen you see your SPark Page, on the upper right corner will be a button that says, My shared food/fitness. People can click on that and see your trackers.
As for how many calories you are burning...That is a difficult one. I wear a fitbit and a heart rate monitor which track my calories for me. I am guessing you do not do that. Instead you must find something on the SPark fitness list that is similar to what you have done. Is it like Aerobic exercise? If so, type in Aerobics, and choose the level - is it vigorous, or moderate? Then type in how long you did it - 30 minutes. It will automatically calculate how manuy calories you burned and track them.
I hope that makes sense. If not, let me know and I will try again.