* where can we find a good mining sites or Apps?
* Did it has is own risks different from bitcoin investment?
* what benefit can we stand to gain mining bitcoin or altcoins?
*Mining sites or apps or cloud mining* are scam if you invest any money in it the fastest way to lose that money, it's like throwing money on the street and waiting for it to double.
Investing in bitcoin is either by keeping it after buying it or trading it, as for cloud mining, it is scam.
If you buy miners and have enough knowledge in addition to a good plan, low energy prices, cooling and some other factors then it will be profitable.