The first thing that makes a website safe is an SSL certificate — you’ll see a little padlock icon in your search bar and the website will begin with https instead of http. You can also look for clearly displayed contact information such as a phone number, email address, physical address, and/or links to social media accounts. Other good signs are a verifiable trust seal and a privacy policy that explains how your info will be collected, used, and protected.
Websites that display suspicious pop-up ads, have tons of grammatical/spelling mistakes, and misspelled domain names should be avoided. Having an antivirus installed with a safe browsing extension is a good way to avoid visiting dangerous sites.