So the problem with n8n being unable to start without first stopping Apache should be easy to solve. Remove the whole traefik: section from your docker-compose.yml file and add a new section like below to n8n: instead:
ports:
- "5678:5678"
This will mean n8n is listening on port 5678 after starting rather than 80 or 443.
However, this does not redirect traffic from n8n.opendream.in port 443 to your n8n port 5678 on which n8n is listening on.
This is where a reverse proxy set up comes into play, which receives all requests from the internet and distributes them to your internal services like so:
(in this example picture it says backend servers, but it might as well be n8n and other docker containers)
This isn’t something I can help with configuring on Apache though unfortunately. You can check out the article behind the above image which might be helpful (but again, I am not familiar with Apache and can’t judge that):
This is a steep learning curve though if this is the first time you do this and as per the thread linked further up isn’t straightforward.