You are going to need a lot of blocks for this build so you should better get to farming. As for the blocks themselves, you can pretty much use anything. Cobblestone and Wood are the most common ...
Minecraft Tutorial - How to Create a Mob Trap and Item Collection Machine by drunkoncustard. Note that to speed up the process, this machine was created in Minecraft's Infdev mode.
Need XP fast in survival? This tutorial shows you how to build the easiest mob XP farm in Minecraft 1.21+ — no spawner required! Works in both Java and Bedrock Edition, fully survival-friendly. What ...