Well just remember the basic things, like tag rules and id attributes.
Remember a html element in its most basic form is an opening tag, some content, and a closing tag.
If you need anymore help then there’s this AMAZING website called w3 schools. It helps me so much and it breaks down every single thing there is to do with JavaScript. You should definetely check it out.
If my explanation wasn’t good at the beginning (sorry!) then w3 schools will deffo steer you in the right direction.
Hope this helps!