Each version of Elements is a separate program and you have to pay for each one. In other words, having Elements 2020 on your Windows machine does not entitle you to a free copy of Elements 2025 on your Mac. In fact, depending on whether you originally purchased a dual platform license, you may not even be able to download a free copy of Elements 2020 for your Mac. The only way you can find out is to go to the Products page of your Adobe account and see whether there is a download link for a Mac. That page will show a listing of Elements 18 for the program known as Elements 2020.
And even if you have a Mac license for Elements 2020, it may not work on a Mac with the latest Operating System. (I only know enough about Macs to warn you of that possibility.)
Now, if your question includes how to get your Organizer catalog from Windows to Mac, take a look at this Adobe HelpX article.