Resize Partition

[mahesh]

I have Ubuntu 20.04 on my HDD and I want to shrink the Ubuntu partition but I am not sure what partition it is.I tried using gparted but I dont understand what to do there either.Can someone walk me through how to shrink this partition please.
This is what I have dev/sda1 System partition
dev/sda2 465 GB
dev/sda3 1mb
I tried to alter dev/sda3 to 50GB but I ended up with only 1mb to
As you can see,I dont need 465 GB so I am trying to make a partition of 50GB to put another OS on.