Hi NadiaBano2,
Thanks for posting in the forum.
From your post, I believe you have an Office 365 subscription and you are trying to access SharePoint online.
To use SharePoint Online, you don'tneed to install any software. Instead, just connect through your web browser.
- Sign in to your work or school account at office.com/signin.
- Select the SharePoint tile on the on the Office 365 home page, or in the app launcher.
For detail information, see Sign in to SharePoint Online
If you have any doubt or need further help, please let me know.
Thanks,
Neha