ConversionXL and Conversion Rate Experts are excellent places to begin exploring the various tests you may run. Swiped is another website that displays targeted copy tests.
Moreover, with the help of Wayback Machine, you can investigate your rivals and learn about the many experiments they have conducted in the past. Because they have stuck with it for so long, it must be serving them well. After all this, you should absolutely check out Google Search Console. Your Google rankings, including position, ranked keywords, and referring pages, are all shown for your perusal. After that, you can try out your selected keywords in a 30-day trial.