Dude good for you! It's so hard on your body sitting in front of a computer for long hours (I know, I do it too), it's great to get out and walk even a few minutes a day. I'm no good at it but my wife hates being stuck in the house so she usually gets us out even for a short walk most days. I sometimes get that pain in my shins too but the more regularly you go out the less it will happen, your body will adapt to the new routine. Changing eating habits is probably the healthiest thing you can do, that's the one that is hardest for me, but honestly even just cutting out soda will be huge, there is so much unnecessary sugar in it. Ive heard mixed things about coffee though, some say its fine some say its better to cut it out in order to just keep up with the healthy mentality. I drink black coffee mostly though and it has almost no calories so I don't feel bad about that one, plus Im super addicted 😂. Keep up the good work, you will never regret working on your health! Oh also, something that helped me stay motivated in the past was wearing a fitness tracker. They are pretty cheap these days and they have really helped me to keep up a good routine.