I made a wall calendar using Dakboard and I need a physical F5 button for refresh my web kiosk. I was thing using a button in gpio. can you help me to do that?

Hi, I’m new to Raspberry pi & linux. I don’t know much about coding but i can understand by reading.
I also want my pi to auto connect to open wifi network. Can you help me to do that? Please post here a step by step coding. I connect to my pi via SSH from my computer.
PLEASE.