A paper-trading system starts with a virtual balance and a simulated portfolio. You choose a symbol, quantity, order type, and price rule, then submit an order instead of sending it to a live exchange.
Order and position
The system marks the order as filled according to its simulation rules. It then records the position, average entry price, available balance, and unrealized or realized profit and loss.
Build a process
Use the same rules you would use in live trading: define risk before entry, record the reason for the trade, and review the result after closing it.