For Christmas, I got an Arduino Uno, and was wondering if I could code it with Scratch instead of learning a new coding language?

You can, actually. I know that you can code Arduino Uno using mBlock 3 that uses Scratch 2.0 and I’ve been using it all along they have a web version but it’s not available to the latest Chrome and macOS. But, what I didn’t knew is that they now have mBlock 5 which has a lot of features and it uses Scratch 3.0 and this is the web version. I think you should use mBlock 5 but I’ve never tried it. Btw I use the Arduino Uno for my school group project.

Take a look at s3-extend.

You can use CodeSkool to program any microcontroller and even connect things like ESP32, MicroBit, Pico, etc. to Scratch.
Here is a demo video of using Potentiometer JoyStick with ESP32 and CodeSkool.
https://www.youtube.com/watch?v=xG9ryJ9Loxg

kkk

Use Onegpio arduino extension in electramod.

Yes, you can!
There’s a version of Scratch at pishi.ai that already includes an Arduino extension — you can connect your Uno over USB and control LEDs, sensors, and motors directly with Scratch blocks.
It’s a great way to learn hardware first, before moving on to C++.