A copper hotwater line goes to the washer (how do I plug that up after unscrewing it?).
If it is plumbed solid, you will have to cut the pipe and cap it. I'd do it close to the supply line. You could plan for the future and instead of a cap, install a cutoff valve that would accept flexible line.

And an electric source is hooked up (where do I disconnect it?)

If it is not plugged in (look under the dishwasher follow the wire to the wall) then you will either have to go the the junction box where it connects to the power source or cut and strip the outter insulation on the cable a few inches then put a wire nut on the black and white wires individually, NOT together) Bend the black wire back and tape it to the cable. Be sure there is no way the black and white wires can ever come into contact with each other or that the black can contact any metal conductor. The bare copper ground can just be clipped off. Check to be sure that there is not just a regular plug on the end of the wire first.