Need to have pop up when customers select Local Pickup

[LeFoCo]

Not sure if this is the correct board, let me know if it's better asked on another.

Many times customers are in such a rush to get their order placed that they don't pay attention to what shipping option they've selected, or they just see the $0 cost for local pickup and select that.

I need to do 1 of 2 things or both:

• default shipping set to 'Standard'
• have a pop up display when customer selects Local Pick up to warn them the order is not a shipping order

I haven't seen an app that will do this.  Anyone know how to script this?  

Currently using Dawn theme

Thx in advance!

Steve