After a new account successfully registered, 10 BTC will be given to the simulated account, which can be traded at any time.
When successfully switching to the simulated trading mode, you will see "You are currently working on a simulation experience" sentence on the top of the interface.
Click the trading pair you want, and enter its trading page.
Then you can choose market or limit to trade as needed. Limit order, namely pending order, means you are allowed to set the price of buying up or buying down, and you can trade when the market price reaches the price you set.
Market order means that you needn’t set the buy-in price, and you can buy up or buy down according to the market price at that moment as long as you enter the volume you want to buy or sell.