To upload the Avatar drag the Scene File (the one with the Unity symbol) called "Mayu" into the hierachy to the left. Log in via VRChat SDK -> settings, then navigate to VRChat SDK -> Show Build Control Panel and follow the assistant. You may have to wait a bit for it to load.
Error: Model is above Poly Limit Solution: Locate ~/Assets/VRCSDK/Dependencies/VRChat/Editor/VRC_SdkControlPanel.cs then search for "void OnGUIAvatarCheck(VRCSDK2.VRC_AvatarDescriptor avatar)" and set the polycount to 64000 in the 3 rows below where it says "polycount < 15000". The UnityPackage should replace the file on its own though.
Error: No textures Solution: Start a fresh project and import Cubed Shaders before importing the model
Error: Missing Scripts, no dynamic bones You will need to have access to the Dynamic Bones package from the unity asset store (costs 20€) or otherwise to have hair and the skirt move around. If you have the package, import the dynamic bones plugin first, along with the VRChat SDK and cubed shaders, in a fresh project.
dude, everytime i open this package into my unity project it crashes my vrcsdk so i have to open a new project and install sdk again, plus i cant upload the avatar in the end
I have run a test and let some friends try it, it all went well for them. Try making a new unity project from scratch, import the VRCSDK, cubed shaders and dynamic bones (if you have that). Then after you have done this import this package and look for the Mayu Scene file with the Unity logo ( https://i.imgur.com/ewNUjJf.png ) and doubleclick it. These are the steps I have done to test the package.