Whoa!
Network switches are often wired very differently then non-networked switches. You can’t just swap them out for what’s there.
In particular, if I understand what you’re saying, if you have a three-way setup you must have auxiliary switches which are specifically designed to work with the master. So you need to replace all the switches, not just the master. You can’t wait and change out the auxiliaries later, there’s a very real danger of burning out your new master switch.
As for the other stuff, the first thing you need to do is map every segment of every circuit so that you know what it does.
Then you read the user guide for the specific model of the switch that you are installing to make sure you are wiring everything correctly.
( actually, the very first thing you should do is take photographs of both the front and back of the existing switches, including the screw connections, so you can see exactly how everything was in case you need to put it back.)
I’ll leave it to others to comment on any specific wiring issues, but from a device standpoint, you need to replace a three-way as a complete set, not do one switch now and the others later.
If you are interested in learning more about all of this, most Home Depot’s have classes on how to install a light switch and you will at least learn how to use the wiring tools follow a circuit. The classes don’t cover networked switches, but since Home Depot does sell the GE Zwave switches, the instructor can often help with specific questions on those models.