Hey @TomLaizy , there are a few things to point out.
If you were using the volume n8n_data before, you would just reuse the very same volume. No need to create it again. Using the same volume should allow you retaining the very same workflows and credentials. However, it is a different matter if your current instance uses a different volume or even a local filesystem.
In order to upgrade, you need to point out to the version you want to upgrade to. For example, this command indicates that you want to spin up the latest version of n8n
sudo docker run -it --rm --name n8n -p 5678:5678 \
-v n8n_data:/home/node/.n8n docker.n8n.io/n8nio/n8n:latest
# ^^^^^^^^ (reusing existing volume) ^^^^^^ (latest version)