I have started learning react.js from today, any tips?

What kind of web development? Like https://www.uclusion.com is built in React but so is our product. For instance for a simple website I added the flipping on our landing page like this

function Home() {
    const [contentTimerState, contentTimerDispatch] = useReducer((state, action) => {
        const { contentVersion, previousOtherContentVersion } = state;
        if (action === 'flip') {
            if (contentVersion === 'one') {
                if (previousOtherContentVersion === 'two') {
                    return {contentVersion: 'three', previousOtherContentVersion: 'three'};
                } else if (previousOtherContentVersion === 'three') {
                    return {contentVersion: 'two', previousOtherContentVersion: 'two'};
                }
            } else if (contentVersion === 'two' || contentVersion === 'three') {
                return { contentVersion: 'one', previousOtherContentVersion };
            }
        }
        return state;
    }, { contentVersion: 'one', previousOtherContentVersion: 'three' });

    useEffect(() => {
        setInterval(() => {
            contentTimerDispatch('flip');
        }, 9000);
    }, []);

    const { contentVersion } = contentTimerState;

    return(
        <div>
            <header className="app-header">
                <img src={logo} alt="logo" className="logo"/>
            </header>
            <div className="screen home-screen">
                <div className="container">
                    <div className="home-container">
                        {contentVersion === 'three' && (

but its mostly about CSS and styling which I needed help with. Using React for a SaaS PWA product though is a whole different thing.