I have a concrete porch and wondered what is the best way to attatch light to it for the Christmas period.?

your best start would be to get some quotes/bids on doing this work and get several === you do not need to feel obligated AND you might get some good ideas of how to set up the electrical wiring and wall sockets === listen and do not say that you are considering D I Y to do this work ...... drop down cable from ceiling connection or thru the wall under the windows for the wall plug sockets [[[[ all outdoor connections should have weather proof covers as these connections are used only for a season........ it will not work to only have one socket as that is a big load -- needs to be several wall sockets ....

If it's brick, you can buy these clips at amazon.

https://www.amazon.com/Brick-Clip-Hooks-Height-4-P...

If it's smooth concrete, you might be able to use "Command strip" hooks.

If it's stucco, You can either start drilling or use fishing line to suspend the corners from a higher point.

Don't.

drill a small hole about an inch and half deep and and use a cup hook on a rawl plug.

cbs or solid concrete? with cbs, I installed screw type hangers into the mortar between the courses.