When I run the shower or the bathroom sink, the commode bubbles and almost all the water gos out of it. Even the second bathroom does it. What do you think the issue is?

While bubbles indicate a clog on down the line you describe a clogged vent. ( Are you sure it isn't a gurgle you hear?) Vents relieve the suction caused by a flush or draining water. If the vent's blocked the fixture will attempt to vent through the nearest trap. In this case your toilet. It's the suction that's pulling the water out of your toilet. The solution would be to snake the roof vents on each bathroom. Put out enough snake to reach the bas and 20 feet more. Good luck, tom