Replacing a cracked galvanized pipe

[Chillumgod]

It turns out that I turned on the sprinkler system valve for the spring and the outside pipe whoooshed out water from the cracked pipe. The crack is in the 1/2-inch galvanized pipe section. I tried JD Waterweld to seal the leak but turns out that instead of a pressure spray, I have a few drops leaking now, guessing that it would rapidly open up with the pressure. I also sprayed it with flex seal but I doubt that it would do anything at this stage. I am guessing I would need to cut the pipes and somehow couple some new pipe sections. I have worked on house projects but never a plumbing project and it looks exciting to start. Since this is outside the house, the chances of flooding the house are unlikely I am attaching a picture of the crack. Please help me with which parts I should replace, the parts and tools to procure, and the instructions. Please review the two attached pictures, one showing the whole system and another showing the location and crack. If you zoom in, you could see the spray of water coming out of the crack. I am really looking forward to your support as I am excited to fix this problem

 

[breplum]

In my opinion, you need a plumber.

 

[Valveman]

Looks like copper not galvanized to me. Gonna need to flux and soldier some new fittings. Outside, so good place to learn. But you might want to watch a plumber do it once before you try it.