With that condition, I would install 1/2 in. to 2 in. EMT conduits everywhere because no amount of planning is enough so it's better to have readily available ways to run extra wires and cables. Cat6 is future proof unless you want to host a datacentre out of your home. I would start my cable schematic from the home server room and deck it out instead of whipping something up. The earlier you start planning your homelab (and think about all the different security scenarios), the earlier you can learn from your mistakes.
With that condition, I would install 1/2 in. to 2 in. EMT conduits everywhere because no amount of planning is enough so it's better to have readily available ways to run extra wires and cables. Cat6 is future proof unless you want to host a datacentre out of your home. I would start my cable schematic from the home server room and deck it out instead of whipping something up. The earlier you start planning your homelab (and think about all the different security scenarios), the earlier you can learn from your mistakes.