1st project, need some help

Very first attempt. I am getting ready to start my first project. I am actually building a custom lightsaber as a xmas gift for my daughter. I am utalizing a premade board for it as the learning curve for that will take too long for me complete in time. That said, I have a nfc ring that never gets used. It gave me the idea to make the saber "coded" to her alone. Now as far as I can tell, the nfc ring won't allow the full functionality of what I desire. I want to make a ble proximity switch that will shut down & wake up with movement. I found a switch online using a tessel 2 board, a relay & ble module. Problem is size. This all needs to fit into a 30mm x 30mm x 12mm area. I believe this will require a main board, a ble module, a relay & some type of sensor that will wake up the ble module when there has been movement. I want the switch to wake up & sleep with movement, but only want the relay active while the approved bluetooth device is present. I do not know enough in this field to even say if my basic parts list is correct.
I found the pico board from mellbell & fanstel has really small ble module. Other than the tessel relay, I am unsure what sensor & relay will work. Not even sure if the pico is sufficient to accomplish this.
Once I complete this switch I will place it inline on the positive side of the battery. Any help would be greatly appreciated. I am sure given enough time I can stumble through this, but help would greatly speed this up. Thanks.

Welcome! It sounds like you have a pretty ambitious first project. I'd strongly suggest you take this in pieces and figure out each one separately and understand it before you try to put it all together. If you can't get it working on a breadboard connected to your PC with the serial monitor open and displaying lots of debug information, I doubt you will get it all together inside a 30x30x12 enclosure with a battery.

Start small, build confidence and then built it all together and then figure out how you can shrink it and/or make it battery powered.

Good Luck!