Step1: create component

1. extend class

                  
                    class ExpenseEntryItem extends React.Component { 

                    }


                    

2. create render function

                    class ExpenseEntryItem extends React.Component { 
                        render() { 
                            
                        } 
                    }

                    

3. create UI

                    class ExpenseEntryItem extends React.Component {
                    render() {
                        return (
                            <div>
                                <div><b>Item:</b> <em>Mango Juice</em></div>
                                <div><b>Amount:</b> <em>30.00</em></div>
                                <div><b>Spend Date:</b> <em>2020-10-10</em></div>
                                <div><b>Category:</b> <em>Food</em></div>
                            </div>
                        );
                    }
                    }

                    

complete web page

                    <div id="react-app"></div>
       
                    <script src="https://unpkg.com/react@17/umd/react.development.js" crossorigin></script>
                    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js" crossorigin></script>
                    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>


                    <script type="text/babel">
                    class ExpenseEntryItem extends React.Component {
                        render() {
                        return (
                            <div>
                                <div><b>Item:</b> <em>Mango Juice</em></div>
                                <div><b>Amount:</b> <em>30.00</em></div>
                                <div><b>Spend Date:</b> <em>2020-10-10</em></div>
                                <div><b>Category:</b> <em>Food</em></div>
                            </div>
                        );
                        }
                    }
                    ReactDOM.render(
                        <ExpenseEntryItem />,
                        document.getElementById('react-app') );
                        
                </script>