If you for some reason need to keep using 32-bit apps, you can purchase software that will allow you to continue using older Mac operating systems alongside Catalina. However, newer versions may also be free on the manufacturer’s website or you can just find alternatives – for example, you might find Google Docs to be an adequate substitute for Word. In some cases, as with Word, you’ll have to buy the updated product. If you want to keep using those apps, it might be worth finding newer, 64-bit versions.