Yeah my 2002 Mazda millennia 2.5 started out with crank no start now it's not crank starters good batteries good looking for relays

Hello, first, ensure you have a fully charged battery that can handle a load. This way, you can make sure you get the cranking power you need. It's no accident or coincidence that the problem started after putting the plugs in. You will want to retrace your steps to make sure every component is connected properly. You should also ensure that the proper cylinders are in the proper order. This means - make sure your ignition wires are properly attached and in the proper firing order. You'll want to check your distributor cap and rotor as well -- if you determine you have no spark. You'll also want to check engine compression and timing. This is a good start; obtaining a good high quality diagnostic tool and a shop manual is extremely helpful also!