I want to trade altcoin but I don't know the very coin that will exist and have future. I need guildance to take this step
The majority of the altcoins now in the market are not potentials, that is why you will noticed and read here in the forum or
even in the other platforms that trade with extreme caution. Because most of them(altcoins) are just a piece of shit.
That is why you to make your own research before investing unto it. Just trade what you can afford lose in.