I am looking to claim a few charitable donations made from 2020-2022 that were NOT claimed. They were however not listed on these previous years tax submission, this ok?

Yes. Just make sure you have the receipts just in case the CRA asks for them.

Would these count as "carried forward" donations, or would they be "new" donations, even though they were made in a previous year?

@SHung614 They would be new. "Carried Forward" donations would be ones that you reported on a previous return, but didn't claim the deduction for on those returns.