Do i need to worry about the three doshas - vata, pitta, kapha?

If you follow the satvic lifestyle, you do not need to worry about the three doshas. Religiously following the complete satvic lifestyle will ensure that your health improves, irrespective of the dosha that you have. 

Mother Nature does not discriminate. Once we start following her rules, we gain good health irrespective of our body constitution.