Hi ghaidaa273
Welcome to the Apple (user-to-user) Community.
Re: How can I upgrade my software.
Backing up all your current data is always a wise first step.
Wondering which MacBook Air Model you are wanting to update:
How to: Identify your MacBook Air model – Apple Support
It is quite a big ask to update from MacOS 10.15 to the newest MacOS 13 in one go.
Eg: Your MacBook Air may not be compatible with the newest Mac OS 13.
or may need to update to an earlier version first, and work up.
macOS Ventura is compatible with these computers - Apple Support
macOS Monterey is compatible with these computers
macOS Big Sur is compatible with these computers
macOS Catalina is compatible with these computers - Apple Support
How to download macOS - Apple Support (including older versions)
If needed:
You might want to reach out to the MacBookAir support Team:
There is a "Get Support" link (online chat, phone, eMail etc.) at the bottom of their website (link below)
MacBook Air - Official Apple Support
All the best :-)