I'm sorry to hear that you're experiencing difficulties with your blender plugin and skins. It can be frustrating to encounter technical issues, but there are resources available to help you address these problems.
If you're having trouble with the UVs of the crate on importing, you may want to check if the crate has any overlapping or disconnected UVs. These issues can cause problems with texture mapping and can be resolved by unwrapping the mesh correctly.
As for the skins, if you're not a graphics designer, you may want to consider using pre-made textures or seeking assistance from a graphic designer. There are many websites that offer free and paid textures that you can use to enhance the appearance of your models.
Additionally, you can look into online communities and forums dedicated to Blender and 3D modeling. These communities can provide valuable advice and guidance on technical issues and artistic direction. Don't hesitate to ask for help or feedback from other users who may have more experience in these areas.