Did you ever see a website that looks really cool and want to make one like it? Assuming you're doing is for fun or a personal site, there is a wide range of tools that can help you achieve the exciting effects you want to emulate. If you work for an agency, you may have limited options, depending on the client's desires and your role in the site's development.
If you want animations to trigger when a user scrolls vertically or horizontally, consider ScrollTrigger using the GreenSock Animation Platform. ScrollTrigger allows you to start your animations when a user reaches a specified spot while scrolling. You could animate a timeline, construct or deconstruct an object, and more.
If you see a website with an animated background you want to draw inspiration from, there are sites where you can find free aminated backgrounds and videos that don't require attribution for commercial projects. You can also use CSS to create amazing background effects that will engage visitors.
Drawing inspiration from another website isn't stealing, as long as you don't copy the site exactly. If you find a site that is engaging, there's a good chance others will too. For more information click here https://v.redd.it/j3da8fzjurq61.