We just bought a house with new plumbing. Every time I use the washing machine and it reaches the spin cycle and water drains out my toilet fills with water and large air bubbles come out of it. Also water filled in the shower. I have looked for the air vent on the roof to see if it was still capped off... that's not it. I snaked the shower drain and put draino down it and now the water isn't coming up in the shower but I still have the toilet problem. First time homeowner... Please help!

You bought a house with mostly new plumbing. It appears the old drains and vents aren't new. Your toilet is trying to act as a vent since your vent stack is clogged. It may appear to the eye to look OK but its likely clogged well out of sight. Rent a rodding machine and rod from the roof enough to reach roof to basement floor plus 15'. I think this will get you going.