Primitive Start adds a few features to spice up the standard tree-punching start of a new Minecraft world. Instead of immediately sprinting to your nearest tree and punching it, you now have to start with sprinting to your nearest animal. After murdering these poor, innocent animals for their bones, you can gather some sticks by breaking leaves.
You'll need quite a few sticks, because you need to craft some planks using them. Alternatively, you can explore for structures made of wooden planks, such as villages, to make a crafting table. Combine your bones and sticks to craft bone tools, which are on par with the incredible wooden toolset.
Before venturing into a cave, you might want a better weapon. If you are able to make a bow, you can now craft bone arrows for it, using some leftover bones from before instead of flint. If you find it difficult to gather enough feathers, you can now pluck them off of chickens using shears. This should give you quite a bit of ammo to survive the caves.
You can now make stone tools, however, stone isn't as strong as you'd like it to be, and it sadly can't mine iron. You can mine a different metal though, copper. You can use copper to make a smithing table, which can then be used to reinforce your bone tools. Reinforced bone tools are on par with iron tools, so you can now continue into the midgame as normal.
