upgrading to OS monterey from Mojave.

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install.  For Best results use Safari to commence the download as Others may not work.

Safari will open a redirect and open the Apple Store where the download can commence.

Computer Qualify for the Monterey upgrade

macOS Big Sur 11 hardware requirements

macOS Catalina 10.15 hardware requirements - Suggestion is to move up to Catalina then move up to Big Sur and eventually up to Monterey

Tips Big Sir Upgrade Released Nov 2020

Tips Monterey Upgrade  Released Oct 25, 2021

Make Time Machine Backup  is very useful and can be used to Revert to Previous Working macOS

Notation - Mojave is the Last version to support 32 bit applications / extensions and Drivers. Catalina, Big Sur & Monterey supports only 64 bit and there is no workaround.

I would recommend making a TimeMachine backup first in case there is any data loss, but it isn’t required. Also, recognize that macOS Monterey (or any version Catalina or newer) doesn’t have iTunes anymore and doesn’t have any support for 32 bit apps. To make a TimeMachine backup, follow the steps in the article below.

Back up your Mac with Time Machine - Apple Support

Tips Monterey Upgrade  and do suggest taking a moment to read some important issues that maybe worth knowing before attempting the leap from Mojave to Monterey.

Caution - jumping over all the newer versions and directly to Big Sur  / Monterey on Qualifying computers is Technically possible - there are those who have attempted and were successful. Then there are those who attempted and had less than good results.

If this is a Production or Mission Critical Set-up - a more prudent and measure approach is suggested. 

The above is from observations on the Apple Support Community Forums and IMHO

Big Sur if 64 bit Apps are not a problem for you.

macOS Big Sur - Technical Specifications

General Requirements

OS X 10.9 or later

4GB of memory

35.5GB available storage on macOS Sierra or later*

Some features require an Apple ID; terms apply.

Some features require a compatible internet service provider; fees may apply.

Mac Hardware Requirements

For details about your Mac model, click the Apple icon at the top left of your screen and choose About This Mac. These Mac models are compatible with macOS Big Sur:

MacBook (2015 or later)

MacBook Air (2013 or later)

MacBook Pro (Late 2013 or later)

Mac mini (2014 or later)

iMac (2014 or later)

iMac Pro (2017 or later)

Mac Pro (2013 or later)

Learn about compatibility and how to identify your specific Mac model

Don't use FireFox or WaterFox for this link. it'll mess it up...

https://apps.apple.com/us/app/macos-big-sur/id1526878132?ls=1&mt=12

And caution on 10.15 or higher, to see which Apps will no longer work in 10.15 get Go64...

https://www.stclairsoft.com/Go64/

brenda b.from elk grove wrote:

Thats really to bad about iTunes. though I am using amazon music mostly, there are songs that I have that I will have to upgrade to amazon unlimited to listen to.

Hi,

Monterey has the Music app to replace the songs/music portion of iTunes, so you don't have to worry about that.

Also, in addition to apps, try to determine if your existing peripherals like printer, scanner, etc. will work in Monterey.

Download Go64 and scan your Mac to see which of your apps are 32 bit and will need to be upgraded/replaced: https://www.stclairsoft.com/Go64/

Some apps may be 64 bit but still not run on Monterey; you can check them out here: https://roaringapps.com/apps

Yep. iTunes was broken up into the Music, TV, and Podcasts apps. The device management capabilities were incorporated into Finder. Everything has the same functionality as iTunes, it just is no longer in a really big, laggy application.