- you don't need the extra 'will' as you are already talking about the future ("you will be able to")
- "try to undertake" is strange, as to "undertake" is to commit to doing something - you can't try to undertake, you either do or don't undertake.
- "near future", not "nearest"
so:
"if you follow this line of behavior you will be able to achieve tangible results in everything you undertake in the near future"