Im not an excepert and my english is not so good too but, Ill try to do my best here....

What I did is: I've started to walk 15 min, later added 30 min then 45 then 1 hour ...and always, always, always with music in my ears - best motivation.
When I felt good with my walking I add few jogging on the way, and slowly slowly add more and more , till I could jogge for 1 hour...now I can jog 10-15 miles - and again, only with good music - must have!!!!!
Always think that what you're doing is only for your own well been... to be healthy and younger - for me
NEVER think doing sport = losing weigt.
This never work for me. Ive alway gain and gain and gain weight... BUT the moment I did it for myself !!!- everything change, include my diet.
Anyway... that's how it is working for me!.... by sharing it with you I hope I help in some way...... keep on doing it for you only