I want to start trading in Bitcoin to dollar,
but I looking for someone sends me mesages
every day tells me it's time to buy and it's time to sell.
Where can I find this person? 
I think your request for who will give you information on when to sell and when to buy in trading currency is the most deadly decision for one to make in trading currency. If you have no time and experience to trade isn't better you stay away from it than to gamble with money which at the end you will end up loosing it as a result of your inexperience and someone decision.