Depends on how good your skill and how experienced you are with trading, if you got a good skill then you can earn in a day, but sometimes you need more than a month before you can earn profit, the most important to know what coins to buy and to trade
Nah, skill is another factor, the only real factor that determines how long a trade could last is the market itself. The pump and dump are decided by the market. Even if you're kind of skilled trader who always got high profit but if the market is pretty stable and rarely have movements, it seems that your trade will take forever.
And in my opinion, different coin have a different time to pump and dump, most of it uncertain though.