On iPhones, iPads (under 10.1 inches), and Android phones, the Word, Excel, and PowerPoint apps are free for basic editing. To unlock advanced features, you need a subscription, but for most home users, the free tier works fine.
If you are looking for the interface and functionality of that era, you are likely looking for (which introduced the XML file formats like .docx) or Office 2010 (which refined the Ribbon interface). Microsoft Office 2009 Free Download With Product Key
If you have a school email, you likely qualify for the full desktop suite for free. On iPhones, iPads (under 10
A powerful, completely free, and open-source alternative that is compatible with all Microsoft Office file formats (.docx, .xlsx, .pptx). iPads (under 10.1 inches)