maybe you can try to watch in youtube there are many tutorial for beginners on how to trade in cryptocurrency and you can start for only $20 just practice first how to earn profit with $20.
Youtube is full of shitcoin shill and idiots with their own propaganda pumping their own shitcoins. Its the last place to learn about crypto trading. The basics of trading remains the same though. However if people are no swayed by those shills then it can be a good idea. This would be better if the person has some idea of crypto from beforehand and then ventures into the youtube shill breeding videos.
There is no exact amount to be used in trading, you can trade whatever amount as long as you consider the transaction charge, because in every trading there is transaction charge, You need to consider it so that you can decide whether to sell it on lower or higher price by knowing your expected profit after deducted the transaction charge.
Good point. Teeny weeny transactions will still take same fees and thus if you have some spare balance consider holding it is the exchange rather than trying to buy some other altcoin. This happens commonly when people are buying a bunch of coins during a dump.
The more the money you invest the more the profit will be. There is no limit for investment in bitcoin. As much you can invest will be better for earning more and more money. You can also start from 500 dollars or less but then your profit margin will also be very low. Just think starting trade with 500 dollars and 50000 dollars which in will be more profitable?