I can be driving my car and stop put it in reverse and it won't move. I can then put it in drive and it won't go. If I turn the car off for a little while, it works fine. What is wrong with my car?

Check for an out of adjustment or faulty automatic transmission gear position switch:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post258005

Thank You. I have heard rave reviews of your advice. Do you think it will be costly?

It shouldn't be.