Most open source systems have a community around them offering free support through different channels. Look at the website of the system to find out what they are. Typically, there will be a mix of chat and forum-like support options. The chats are a good tool for quick questions, for connecting with the community in general and to stay up-to-date on current events. The biggest advantage of a chat is instantaneous, the biggest disadvantage is you only reach the people online simultaneously and your question may get lost.
The more persistent options like forums, mailing-lists or newsgroups are a better option, if you want to reach more people, have a more complicated question or need to show longer examples of your code. Read up on existing code of conducts or descriptions of what the different options should be used for. For example, Stack Overflow is not a platform for discussions but for concrete questions and answers.
Keep in mind that people are supporting you for free, and you have neither a guarantee nor right to get an answer.