To watch videos on YouTube, you can follow these steps:

Open a Web Browser: Open your preferred web browser on your computer or mobile device.

Go to YouTube: Type "youtube.com" into the address bar of your browser and press Enter.  This will take you to the YouTube homepage.

Search for Videos: You can use the search bar at the top of the YouTube homepage to search for specific videos or topics.  Enter the keywords for the video you want to watch and press Enter.  You can also browse through the recommended videos on the homepage or explore different categories by clicking on the menu icon (three horizontal lines) in the top-left corner of the page.

Select a Video: Once you find the video you want to watch, click on its thumbnail image to open it.

Watch the Video: The video will start playing automatically.  You can adjust the volume, pause or play the video, and view it in full-screen mode by using the controls located at the bottom of the video player.

Interact with the Video: While watching the video, you can like, dislike, comment, share, or subscribe to the channel of the video creator using the buttons below the video player.

Explore Related Videos: After you finish watching a video, YouTube will suggest related videos based on your viewing history and preferences.  You can continue watching related videos or search for new ones using the search bar.

Sign in (Optional): If you want to like, comment, or subscribe to channels, you'll need to sign in to your Google account.  You can do this by clicking the "Sign In" button in the top-right corner of the YouTube homepage and entering your Google account credentials.

That's it!  You're now ready to watch videos on YouTube.  Enjoy!