#Starting Jenkins
sudo systemctl start jenkins
#Configure Jenkins to start at boot
sudo systemctl enable jenkins
#Checking status of jenkins
sudo systemctl status jenkins
#Will show below output if everything is working fine:
#Loaded: loaded (/lib/systemd/system/jenkins.service; enabled; vendor preset: enabled)
#Active: active (running) since Tue 2018-11-13 16:19:01 +03; 4min 57s ago