If you know what you want to trade, you need a portfolio. There are big differences in the fees of the depository providers. This can also result in very different costs. With one provider, every transaction can be billed and with another, simply storing your investments.
How to learn to trade
Before you begin randomly opening securities account to buy and sell shares, you must do some dry runs. You can trade without money through paper trading. Many providers offer this. With this kind of trading, you can see how your sales and purchases would affect you. There are no genuine purchases so your risk is zero.