Docker wont start, because of a daemon?

Hey guys, I’m new in this forum, because I never had problems with docker, but today, i had to switch to a different server, where docker version 18.09.2 build 6247962 is installed.

I need docker for my webcrawler. I’m not sure, if i already got the right image, so tried:
sudo docker pull scrapinghub/splash

After executing this command i got following error:

docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.

I also tried chmod 666 /usr/run/docker.sock, because this was a “solution” i read about on stackoverflow.

When i execute service docker status i get:

docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: failed (Result: start-limit-hit) since Fri 2020-10-23 11:46:30 CEST; 43min ago
Docs: https://docs.docker.com
Process: 7881 ExecStart=/usr/bin/dockerd -H fd:// (code=exited, status=1/FAILURE)
Main PID: 7881 (code=exited, status=1/FAILURE)

Also if i execute docker ps, to see my containers, i get:

Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.39/containers/json: dial unix /var/run/docker.sock: connect: permission denied

when executing as root i get again:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

Sorry if this is potential duplicate, but i cant go ahead, if i do not solve this problem.

Since I’m kind of new, i am very afraid of doing or testing things, pls i really need help with that