Here is a list of 14 things you can do to improve your health.
(I could have added more but this is a good start point).
None of these things are rocket science, but if you start small with one habit then build upon that you can really start to see huge improvements. There is no special order in which to start so I suggest if you want to try and improve your health, then choose the one that will have the biggest impact straight away. This is usually the hardest one to do so it's scary. Or, if you're not brave enough to do the scary one, then choose the one that you know for sure you can do for a quick win to motivate you towards the next habit.
How long do you think it would take to do all of these things as standard? Hint - it's not 30 days ;)