Bedrock is the version that is on the consoles like the switch. Java has support for texture packs and mods and gets the new updates before Bedrock.
So if you want to play with your switch and pc together then bedrock, but if you only want to play between pcs then Java for sure,
Don't buy Realms, if you can run a server off one of the pcs then its free. On the minecraft site there is a guide how to set up a server. But a LAN would be easier if you are all on the same network.
You could try creative mode first and build something together as a start as well