Hi @JeeshA,
Regarding exercise, yes, physical activity is recommended for general health and is not contraindicated by hepatitis B.
This issue of protein powder and creatine has been addressed in previous threads:
Essentially, supplements are very poorly regulated, so anything could be in there - it is therefore difficult to say if a particular one could be harmful or not. Moreover, no supplements have been shown by clinical trials to consistently and meaningfully improve liver health - so the benefits of these supplements are not obvious.
Hope this helps,
Thomas