What can an amateur astronomer do to help the public enjoy the eclipse?

This is easy…just show up!  Find a location in your area where there are likely to me many people, or contact your local museum and get on their list of ‘eclipse helpers’. If you have a telescope with the right filters, bring it with you and set it up so that  people can view the eclipse before totality starts. Also, if you have one of those special ‘Hydrogen-alpha’ filters you can use it to show people what the surface of the sun looks like .There may still be a few sunspots to view this late in the current sunspot cycle. Be prepared to answer all kinds of unusual questions, so make sure you have done your homework on the basic details about the sun, its corona and other features such as its size relative to Earth and other similar things.