Is there a place where I can post my error messages without giving too much private information away, and where the information isn't public, if it contains private information about my system? I'd like to help resolve some issues, but am concerned about posting publicly the info from the clipboard which Tor collects in its error log. Can someone explain whether it is private information or not too, as I am unaware of what to do, but would like both the help to establish a good connection, and at the same time, a secure site for all decent users.
First it is important to know what you consider private/sensitive information. @canonizing ironize wrote some good hints in their comment.
By default Tor sets
SafeLogging which means that IP addresses and other information which Tor considers sensitive is redacted. Furthermore you should check the logging information before posting it somewhere if it contains more sensitive information.
Another way to protect information from future use is to use a paste site which automatically deletes the content after some time. However this doesn't prevent anyone from copying this information and making it public at some other place.
If it is a bug in Tor, you can make an entry in the bug tracker and leave an information there that you can provide more, but sensitive information. This way a developer could contact you and you could send the information in private to this person.
Furthermore you can use one of the contact methods to contact the project privately.
However I would suggest to redact the log as a first step and use publicly available channels.