When I try to install xplosives mod, it says xplosives-1.2.jar was blocked because this type of file can harm your device. This is the first time I've tried to install a mod for minecraft java, so I don't know what to do

If you've downloaded it from our website, it won't harm your computer. You can safely put it in the mods folder and run minecraft.

 Thanks! It took me a while to get forge working, but I have now installed xplosives mod!