I upgraded to Monterey and the toolbar items are too small

If you're referring to the Dock, you'll need to adjust the Dock size at System Preferences > Dock

If you're referring to the menu bar, you'll need to adjust the display resolution for that.

System Preferences > Displays > Scaled resolution and pick one that works best for you.

I’m on my iPhone at the moment and couldn’t remember the exact location or steps to make the menu bar larger, so you’ll have to look at > https://osxdaily.com/2021/10/12/change-menu-bar-size-mac/

Oh, that's a good one. 👏🏽

I've been waiting to learn something new today. 😃

You're welcome.

Please also see the link posted by @den.thed. Good info to know for when you upgrade to Big Sur and beyond. 👍🏽

You’re welcome.

While it helps, don’t expect much because it’s only slightly larger than small. 😕