Exchanges
-You will need to open accounts in Exchanges where you want to trade.
-Binance is a crypto-exchange, account can be opened quite fast.
-Kraken is a crypto-exchange, account can be opened quite fast.
-InteractiveBrokers is a great Stockbroker with cheap commissions. Account can be opened quite fast. They have PDT-rule, but you can also develop your strategies by papertrading.