To be honest, it sounds like you might need to bring in an electrician. Or if you live near a Home Depot, many have classes in how to wire a three-way set up. They won’t apply directly to networked switches, but you’ll learn a lot about the basics of wiring and the tools you use and since Home Depot does sell the switches the instructor may also be able to help you with that.
Anyway, you got a good start on the basic concept. You do need to always have the auxiliary that specifically matches the master. Different brands and even models use different methods for communication and so you have to get the ones that match exactly.
Your first goal should be to wire the master. Once you have that working, you can add the auxiliary.
However, before you add the auxiliary you need to know exactly what every wire segment is doing because networked devices are wired differently than the nonnetworked devices they are replacing. Do it wrong, and you can burn out your brand-new switch.
Also, in the US wire colors are not mandated by code and people can and do use any color for any purpose, sometimes just because it’s the end of the day and there’s only one roll of wire left in the toolbox. So you can’t just follow videos on the Internet, either, because while there’s a “recommended” meaning for each wire color, that doesn’t mean that’s how it was done at that particular switch.
If just reading the user guide that came with the device isn’t enough to direct you, it’s time to get some additional help.
Oh, and before you remove the old switch, label all the wires and take photographs including the back of the switch and the exact screw connectors that the wires connect to so you can see exactly which wire goes to which screw. This can save a lot of headaches later.