Just found diamonds, now what?

I'm just coming back to minecraft for the first time since middle school. It very well could have been 10 years since I played last. I never got that into survival bc I'd usually play minigames on servers like Hypixel and Mineplex.

I just booted up my survival world a day ago. I have a nice little whole in the wall that I call home (with a bed), and I've started construction on a cottage. I also have a chicken coop and a wheat farm. My cottage/farm are next to a river so I can fish and I have been replanting trees so I have a good supply of timber.

I just went to a cave and, WHOA! Caves are WAY bigger than I remember. I felt like I was going deeper and deeper forever. They go way deeper and are also physically larger than I remember. I don't even think I explored the whole thing but I got a bunch of iron, redstone, lapis, and the thing I wanted to talk about: some DIAMONDS.

What do I do now that I have diamonds? I remember when I was a kid everyone was always talking about getting diamonds but now that I have them what should I do? I heard that there's a way to beat minecraft? Should I try to do that now?