It's no secret that Minecraft has evolved a lot over the years. If you are logging back in for the first time since 1.18 started, then you are likely having a bit of trouble finding certain types of ore. Iron ore is extremely important during the first few hours of the game, but it's much harder to find by just digging a random mine shaft.
Typically, iron ore spawns the most within mountains but can also be found between coordinates Y=-24 and Y=56 elsewhere. If you do find a tall mountain, this can change a bit, with iron spawning up to Y=232 with around Y=80 as your prime starting point. The higher you go up from Y=80, the more iron ore you should find.
Mountains are your best chance of finding iron ore, but you should still keep in mind that each world has its own unique RNG. This means that how much iron you find will still be left up to a bit of luck.
Keep in mind that the game may choose to randomly spawn iron veins, but this will be a rarity for most players if you're not in the proper spawning area.
For more on Minecraft, check out Minecraft Jungle Seeds (Bedrock & Java 1.18) on Pro Game Guides!
I start my day by exploring Teyvat in Genshin Impact and end it after reorganizing my apartment in Final Fantasy XIV. I am a diehard fan of N64 era games and will forever feel betrayed that Megaman Legends didn't finish. Outside of gaming, I have spend my time collecting manga, collecting anime figures, and watching anime with my naked cat.