I just installed litematica and whenever i try to load a schematic all the textures glitch out I havent changed any settings

Conflict with Optifine. I dont think the litematica author can do anything with that.
It is well-known issues, previously there was a solution just to disable VBO though it's not possible anymore. VBO is by default always ON and you cannot turn it off.
So, play the game with Optifine, build your mega-super-duper creations without)

(This is in the wrong repo...)
This is caused by shaders in Optifine. Disable shaders (set them to OFF and not Internal) and restart the game.