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? 
If you want to be successful in trading then this kind of state is inappropriate. You shouldn't be needing a person to remind you when to sell and when to buy, you should know it yourself. It's your money at stake so do not entirely trust it to other peoples opinion or whatsoever.
100% true, you can't just ask people what to buy and believe them because we can never be sure if they are telling the truth or just hyping and blame them if you lose your money.
I agree, this is one trait mostly riders commonly have. But I think I've heard about this too, paying someone to tell you this certain coin is pumping or whatsoever. And yes if you really want to be successful in trading, you have to take time also in learning how to trade or learn how to read charts to know which coin is pumping. As they say "knowledge is power", educate yourself so you won't have to rely on what someone has to say because in the end it is you who will benefit from it and not anybody else.
Yeah, I've read that somewhere here that you will avail it for 1 month or I think they offer long term the fee is really high but they said they have profited from this subscription. Oh well that's their choice maybe they're just too lazy to study and do it on their own.