Jenkins is a community-driven project, and it does not provide user support in the common meaning. Nevertheless, there is an active community which might be able to help with the issues you experience. The Jenkins JIRA is NOT a support site. If you need assistance or have general questions, visit us in chat, or email one of the user mailing lists. Also check out the main component's page for specific communication channel references.
Please be aware that most Jenkins components are maintained by volunteers. This means there is no guarantee of a timely response or issue resolution. If you want commercial support for Jenkins, there are companies which offer it. See the list on this Wiki page. Note that this list should not be viewed as endorsement by the Jenkins project, the list is provided for reference.