Minecraft Xbox one edition is really messy when trying to add texture packs, I highly recommend adding a texture pack through realms on to a specific world due to how easy it is, try to use a different texture pack through that process, and if it works then the texture pack you're trying to work with most likely isn't working for some reason.
texture packs from online will automatically install on to minecraft if you run them. If you try to use Java edition textures, they are not supported on minecraft bedrock edition.
Check you mouse and keyboard controls in the settings to make sure that is set to attacking on the left mouse click, if that doesn't work you might have uninstall and reinstall. There is tutorials on YouTube to permanently remove every file of windows 10 edition so you can completely remove all cache of the game.