Exercise "strategy"

Today, I have been told the inevitable.  I need to exercise more.  The truth is, I rarely exercise at all. I barely have an exercise regimen and whatever regiment I have I have trouble following it.  Is getting back on the horse a good way to start exercising again?  I used to exercise on the treadmill and ever since then, I got thrown off track.  Nowadays, I don't have a treadmill, so that threw me and my plans off.  Nowadays my walking  has been slow and my physical ailments have been worse.  I am working on one thing at a time.  However, it doesn't help that one minute I watch videos of T25 in hopes that I would lose weight faster but to keep the muscles going.  It is inspiring and so amazing to see people having such great results in only a few months, but it is too hard and after a while, will I continue? What exercise would be good for me?  What do I like to do?  How long do I wish to exercise for that day?  How many days a week do I wish to exercise?  How do I become specific with my plan? How do I stick with this said plan?  Those are the questions that I need to answer for myself.  I have my own strategy to lose weight which should include exercise, how does it finally mesh with my weight loss goals?