What was the amount with which you started trading
I mean your very basic investment and was that your extra money or required money?
there is no minimum amount to start a trade, but every exchange have a minimum deposit, so we should follow them. i suggest you start with 100$, especially if this is the first time for you. the first time i trade with 250$ and that is my extra money.
In my case I set a minimum amount to myself to start trading is when the value of bitcoin is Higher than $10000 and I bet that if it happen then this could be the starting of improving the status of the crypto market. However everytime could be a best time to start trading and buying coin but before anything else know first the status of the coin you're going to buy/trade.